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1

Engines - Spark Ignition Engines  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Spark Ignition Engines Spark Ignition Engines Thomas Wallner and omni engine Thomas Wallner and the omnivorous engine Background Today the United States import more than 60% of its crude oil and petroleum products. Transportation accounts for a major portion of these imports. Research in this field is focused on reducing the dependency on foreign oil by increasing the engine efficiency on the one hand and blending gasoline with renewable domestic fuels, such as ethanol, on the other. Argonne's Research The main focus of research is on evaluation of advanced combustion concepts and effects of fuel properties on engine efficiency, performance and emissions. The platforms used are a single-cylinder research engine as well as an automotive-size four-cylinder engine with direct fuel injection.

2

Argonne TTRDC - Engines - Home - combustion, compression ignition,  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

* Combustion Visualization * Combustion Visualization * Compression-Ignition * Emissions Control * Fuel Injection and Sprays * Idling * Multi-Dimensional Modeling * Particulate Matter * Spark Ignition Green Racing GREET Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Technology Analysis Transportation Research and Analysis Computing Center Working With Argonne Contact TTRDC Engines Omnivorous engine tested by Thomas Wallner Thomas Wallner tests the omnivorous engine, a type of spark-ignition engine. Argonne's engine research is contributing to advances in technology that will impact the use of conventional and alternative fuels and the design of advanced technology vehicles. Compression Ignition

3

Stoichiometric Compression Ignition (SCI) Engine Concept | Department...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

More Documents & Publications An Experimental Investigation of the Origin of Increased NOx Emissions When Fueling a Heavy-Duty Compression-Ignition Engine with...

4

Engines - Spark Ignition Engines - Direct Injection - Omnivorous Engine  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Direct Injection, Spark-Ignited Engines Direct Injection, Spark-Ignited Engines Omnivorous Engine Omnivorous Engine Setup Omnivorous Engine Setup New engine technology has made possible engines that will operate on a wide variety of fuel inputs, from gasoline to naptha to ethanol to methanol, without driver intervention. Although flexible fuel vehicles have been produced in the millions, their engines have always been optimized for gasoline operation while accepting significant performance and efficiency degradations when using the alternative fuel. This project seeks to combine in-cylinder measurement technology, and advanced controls to optimize spark timing, the quantity and timing of injected fuel, to produce an "omnivorous engine"--one that will be able to run on any liquid spark ignition fuel with optimal efficiency and low

5

Fuel effects in homogeneous charge compression ignition (HCCI) engines  

E-Print Network [OSTI]

Homogenous-charge, compression-ignition (HCCI) combustion is a new method of burning fuel in internal combustion (IC) engines. In an HCCI engine, the fuel and air are premixed prior to combustion, like in a spark-ignition ...

Angelos, John P. (John Phillip)

2009-01-01T23:59:59.000Z

6

Transonic Combustion ?- Injection Strategy Development for Supercritical Gasoline Injection-Ignition in a Light Duty Engine  

Broader source: Energy.gov [DOE]

Novel fuel injection equipment enables knock-free ignition with low noise and smoke in compression-ignition engines and low-particulates in spark-ignition engines.

7

High Fidelity Modeling of Premixed Charge Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Most accurate and detailed chemical kinetic models for fuels of practical interest to engine manufacturers and fuels developers are applied for high fidelity engine analysis of premixed charge compression ignition engines.

8

Advanced CFD Models for High Efficiency Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Advanced CFD models for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion.

9

Simulation of Landfill Gas Performance in a Spark Ignited Engine.  

E-Print Network [OSTI]

?? Computer simulations were performed using KIVA-4 code to determine performance of a spark ignited engine fueled by methane diluted with carbon dioxide to approximate… (more)

Swain, Daniel P.

2010-01-01T23:59:59.000Z

10

Fundamental Studies of Ignition Process in Large Natural Gas Engines Using Laser Spark Ignition  

SciTech Connect (OSTI)

Past research has shown that laser ignition provides a potential means to reduce emissions and improve engine efficiency of gas-fired engines to meet longer-term DOE ARES (Advanced Reciprocating Engine Systems) targets. Despite the potential advantages of laser ignition, the technology is not seeing practical or commercial use. A major impediment in this regard has been the 'open-path' beam delivery used in much of the past research. This mode of delivery is not considered industrially practical owing to safety factors, as well as susceptibility to vibrations, thermal effects etc. The overall goal of our project has been to develop technologies and approaches for practical laser ignition systems. To this end, we are pursuing fiber optically coupled laser ignition system and multiplexing methods for multiple cylinder engine operation. This report summarizes our progress in this regard. A partial summary of our progress includes: development of a figure of merit to guide fiber selection, identification of hollow-core fibers as a potential means of fiber delivery, demonstration of bench-top sparking through hollow-core fibers, single-cylinder engine operation with fiber delivered laser ignition, demonstration of bench-top multiplexing, dual-cylinder engine operation via multiplexed fiber delivered laser ignition, and sparking with fiber lasers. To the best of our knowledge, each of these accomplishments was a first.

Azer Yalin; Bryan Willson

2008-06-30T23:59:59.000Z

11

Exhaust gas recirculation in a homogeneous charge compression ignition engine  

DOE Patents [OSTI]

A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL)

2008-05-27T23:59:59.000Z

12

Comparative studies of methane and propane as fuels for spark ignition and compression ignition engines  

SciTech Connect (OSTI)

The paper reviews the combustion characteristics of the two fuels and sets out to consider their respective performance in both spark ignition and compression ignition engines. Results of comparative tests involving spark ignition engines over a wide range of operating conditions are presented and discussed. Some of the performance characteristics considered are those relating to power output, efficiency, tendency to knock, cyclic variations, optimum spark requirements and exhaust emissions. Similarly, some of the performance characteristics in compression ignition engines considered include power output, efficiency, tendency towards knock and autoignition, exhaust emissions and low operational temperature problems. Finally, the relative operational safety aspects of the two fuels are evaluated. It is then suggested that in this regard, methane has some excellent physical, chemical and combustion characteristics that makes it a particularly safe fuel.

Karim, G.A.; Wierzba, I.

1983-08-01T23:59:59.000Z

13

The effects of EGR and ignition timing on emissions of GDI engine  

Science Journals Connector (OSTI)

The effects of EGR and ignition timing on engine emissions and combustion were studied through an experiment carried out on an air-guided GDI engine. The test results showed that the ignition timing significantly...

LiFeng Zhao; XiuMin Yu; DingChao Qian; Wei Dong…

2013-12-01T23:59:59.000Z

14

High load operation in a homogeneous charge compression ignition engine  

DOE Patents [OSTI]

A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Liechty, Michael P. (Chillicothe, IL); Hardy, William L. (Peoria, IL); Rodman, Anthony (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL)

2008-12-23T23:59:59.000Z

15

Railplug Ignition System for Enhanced Engine Performance and Reduced Maintenance  

SciTech Connect (OSTI)

This Final Technical Report discusses the progress that was made on the experimental and numerical tasks over the duration of this project. The primary objectives of the project were to (1) develop an improved understanding of the spark ignition process, and (2) develop the railplug as an improved ignitor for large bore stationary natural gas engines. We performed fundamental experiments on the physical processes occurring during spark ignition and used the results from these experiments to aid our development of the most complete model of the spark ignition process ever devised. The elements in this model include (1) the dynamic response of the ignition circuit, (2) a chemical kinetics mechanism that is suitable for the reactions that occur in the plasma, (3) conventional flame propagation kinetics, and (4) a multi-dimensional formulation so that bulk flow through the spark gap can be incorporated. This model (i.e., a Fortran code that can be used as a subroutine within an engine modeling code such as KIVA) can be obtained from Prof. Ron Matthews at rdmatt{at}mail.utexas.edu or Prof. DK Ezekoye at dezekoye{at}mail.utexas.edu. Fundamental experiments, engine experiments, and modeling tasks were used to help develop the railplug as a new ignitor for large bore natural gas engines. As the result of these studies, we developed a railplug that could extend the Lean Stability Limit (LSL) of an engine operating at full load on natural gas from {phi} = 0.59 for operation on spark plugs down to {phi} = 0.53 using railplugs with the same delivered energy (0.7 J). However, this delivered energy would rapidly wear out the spark plug. For a conventional delivered energy (<0.05 J), the LSL is {phi} = 0.63 for a spark plug. Further, using a permanent magnet to aid the plasma movement, the LSL was extended to {phi} = 0.54 for a railplug with a delivered energy of only 0.15 J/shot, a typical discharge energy for commercial capacitive discharge ignition systems. Here, it should be noted that railplugs and the associated ignition circuit should not cost much more than a conventional spark ignition system. Additionally, it is believed that the railplug performance can be further improved via continued research and development.

DK Ezekoye; Matt Hall; Ron Matthews

2005-08-01T23:59:59.000Z

16

Turbocharged spark ignition engine modelling and control strategy  

Science Journals Connector (OSTI)

This paper deals with the non-linear modelling and control of a turbocharged spark ignition engine. In the automotive industry, downsizing-based turbocharging is considered as a powerful technique to improve engine performances as fuel economy, pumping loss reduction to increase engine efficiency or driveability optimisation. This method is largely used for diesel engines. For gasoline engines, it is more complex in terms of control. In this work, a simplified control-oriented model is presented and validated using a Smart MCC three cylinders engine data. Then, based on this model, a fuzzy non-linear control law is calculated to achieve the fuel consumption and pumping losses reduction by setting the engine states to a given profile.

D. Khiar; J. Lauber; T.M. Guerra; T. Floquet; G. Colin; Y. Chamaillard

2008-01-01T23:59:59.000Z

17

Closed-loop, variable-valve-timing control of a controlled-auto-ignition engine  

E-Print Network [OSTI]

The objective of this study was to develop a closed-loop controller for use on a Controlled-Auto- Ignition (CAI) / Spark-Ignition (SI) mixed mode engine equipped with a variable-valve-timing (VVT) mechanism. The controller ...

Matthews, Jeffrey A., 1970-

2004-01-01T23:59:59.000Z

18

Gasoline Engine Economy as Affected by the Time of Ignition  

E-Print Network [OSTI]

KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Gasoline Engine Economy as Affected by the Time of Ignition 1907 by George Jay Hopkins This work was digitized by the Scholarly Communications program staff... in the KU Libraries’ Center for Digital Scholarship. http://kuscholarworks.ku.edu Submitted to the University of Kansas in partial fulfillment of the requirements for the Degree of Bachelor of Science GASOLINE ENCUNE ECONOMY as Affected W the Time...

Hopkins, George Jay

1907-01-01T23:59:59.000Z

19

Laser Ignition  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laser Ignition Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable...

20

Review and recent developments of laser ignition for internal combustion engines applications  

Science Journals Connector (OSTI)

Performance of future ignition system for internal combustion engines should be reliable and efficient to enhance and sustain combustion stability, since ignition not only initiates combustion but also influences subsequent combustion. Lean burn systems have been regarded as an advanced combustion approach that could improve thermal efficiency while reducing exhaust gas emissions. However, current engines cannot be operated sufficiently lean due to ignition related problems such as the sluggish flame initiation and propagation along with potential misfiring. A high exhaust gas recirculation engines also has similar potential for emissions improvement, but could also experience similar ignition problems, particularly at idle operation. Similarly, ignition is an important design factor in gas turbine and rocket combustor. Recently, non-conventional ignition techniques such as laser-induced ignition methods have become an attractive field of research in order to replace the conventional spark ignition systems. The fundamentals of conventional laser-induced spark ignition have been previously reviewed. Therefore, the objective of this article is to review progress on the use of such innovative techniques of laser-induced ignition including laser-induced cavity ignition and laser-induced multi-point ignition. In addition, emphasis is given to recent work to explore the feasibility of this interesting technology for practical applications concerning internal combustion engines.

Mohamed H. Morsy

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Diesol: an alternative fuel for compression ignition engines  

SciTech Connect (OSTI)

Physical properties including specific gravity, kinematic viscosity, heat of combustion, flash point, cetane number and distillation curves are presented for several blends of No. 2 diesel fuel and soybean oil. The mixture is referred to as Diesol. The soybean oil received a minimal amount of refining by water-washing to remove most of the lecithin type gums. The Diesol fuels were tested in a Cooperative Fuel Research single cylinder diesel test engine to determine the short time engine performance using soybean oil as a diesel fuel extender. Brake specific fuel consumption, volumetric fuel consumption, exhaust smoke opacity and power were determined. Various blends of Diesol were also tested in a multicylinder diesel commercial power system. Results are presented to show the comparison between Diesol blends and diesel fuel. The fuel properties and engine performance test results indicate that soybean oil would be a viable extender of diesel fuel for compression-ignition engines.

Cochran, B.J.; Baldwin, J.D.C.; Daniel, L.R. Jr.

1981-01-01T23:59:59.000Z

22

Jet Ignition Research for Clean Efficient Combustion Engines Prasanna Chinnathambi, Abdullah Karimi, Manikanda Rajagopal, Razi Nalim  

E-Print Network [OSTI]

-chamber internal combustion engines and in innovative pressure-gain combustors for gas turbine engines. Jet engines using low-cost, low-carbon natural gas need improved methods for ignition of lean mixtures rotor combustor. A wave rotor combustion chamber is best ignited with a jet of hot gas that may come

Zhou, Yaoqi

23

IGNITION TRANSIENT IN AN ETHYLENE FUELED SCRAMJET ENGINE WITH AIR THROTTLING.  

E-Print Network [OSTI]

??This research focuses on the modeling and simulation of ignition transient and subsequent combustion dynamics in an ethylene fueled supersonic combustion ramjet (scramjet) engine. The… (more)

Li, Jian

2009-01-01T23:59:59.000Z

24

Predictive Modeling of a Homogeneous Charge Compression Ignition (HCCI) Engine with EGR Fueled with Diesel  

Science Journals Connector (OSTI)

Homogeneous charge compression ignition (HCCI) combustion integrates features of both spark ignition (SI) and compression ignition (CI) engines, obtaining a promisingly high efficiency in a diesel engine with virtually almost no NOx and soot emissions. ... The objective of the model is to simulate fundamental engine results such as combustion pressure, heat-release rate, indicated mean pressure (IMEP), gas temperature, and exhaust gas emission from easily measured engine parameters. ... Gordon, P. B. The Design and Simulation of a 4 Stroke Engine; Society of Automotive Engineers: Warrendale, PA, 1999. ...

Miguel Torres García; Fco Jiménez-Espadafor Aguilar; Elisa Carvajal Trujillo; José Antonio Becerra Villanueva

2009-09-10T23:59:59.000Z

25

Conversion of a diesel engine to a spark ignition natural gas engine  

SciTech Connect (OSTI)

Requirements for alternatives to diesel-fueled vehicles are developing, particularly in urban centers not in compliance with mandated air quality standards. An operator of fleets of diesel- powered vehicles may be forced to either purchase new vehicles or equip some of the existing fleets with engines designed or modified to run on alternative fuels. In converting existing vehicles, the operator can either replace the existing engine or modify it to burn an alternative fuel. Work described in this report addresses the problem of modifying an existing diesel engine to operate on natural gas. Tecogen has developed a technique for converting turbocharged automotive diesel engines to operate as dedicated spark-ignition engines with natural gas fuel. The engine cycle is converted to a more-complete-expansion cycle in which the expansion ratio of the original engine is unchanged while the effective compression ratio is lowered, so that engine detonation is avoided. The converted natural gas engine, with an expansion ratio higher than in conventional spark- ignition natural gas engines, offers thermal efficiency at wide-open- throttle conditions comparable to its diesel counterpart. This allows field conversion of existing engines. Low exhaust emissions can be achieved when the engine is operated with precise control of the fuel air mixture at stoichiometry with a 3-way catalyst. A Navistar DTA- 466 diesel engine with an expansion ratio of 16.5 to 1 was converted in this way, modifying the cam profiles, increasing the turbocharger boost pressure, incorporating an aftercooler if not already present, and adding a spark-ignition system, natural gas fuel management system, throttle body for load control, and an electronic engine control system. The proof-of-concept engine achieved a power level comparable to that of the diesel engine without detonation. A conversion system was developed for the Navistar DT 466 engine. NOx emissions of 1.5 g/bhp-h have been obtained.

NONE

1996-09-01T23:59:59.000Z

26

The role of fuel in determining the high load limit of controlled auto-ignition engines  

E-Print Network [OSTI]

Controlled Auto-Ignition (CAI) engines have the potential to increase fuel economy while lowering nitrogen oxide and soot emissions. One hurdle that is currently being faced is the engine's inability to operate at high ...

Maria, Amir Gamal

2009-01-01T23:59:59.000Z

27

Laser ignition in internal-combustion engines: Sparkless initiation  

Science Journals Connector (OSTI)

Laser ignition has been implemented in a single-cylinder ... pressure versus crank angle) were obtained for laser ignition with nano- and microsecond pulses of an Nd:YAG laser. The maximum power of microsecond pu...

A. A. Andronov; V. A. Gurin; A. V. Marugin; A. P. Savikin…

2014-08-01T23:59:59.000Z

28

A user-friendly computer simulation of a spark ignition engine  

E-Print Network [OSTI]

A USER-FRIENDLY COMPUTER SIMULATION OF A SPARK IGNITION ENGINE A Thesis by IVAN BERRIOS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1993 Major Subject: Mechanical Engineering A USER-FRIENDLY COMPUTER SIMULATION OF A SPARK IGNITION ENGINE A Thesis by IVAN BERRIOS Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

Berrios, Ivan

2012-06-07T23:59:59.000Z

29

Advanced combustion methods for simultaneous reduction of emissions and fuel consumption of compression ignition engines  

Science Journals Connector (OSTI)

In this work, advanced combustion modes i.e. improved low-temperature combustion (LTC) and reactivity controlled compression ignition (RCCI) have been achieved in a diesel engine. LTC mode has been improved us...

P. Brijesh; A. Chowdhury; S. Sreedhara

2014-07-01T23:59:59.000Z

30

A visualization study of mixture preparation mechanisms for port fuel injected spark ignition engines  

E-Print Network [OSTI]

An experimental study was carried out that examined qualitatively the mixture preparation process in port fuel injected spark ignition engines. The primary variables in this study were intake valve lift, intake valve timing, ...

Costanzo, Vincent S. (Vincent Stanley), 1979-

2004-01-01T23:59:59.000Z

31

Laser Ignition and Laser Induced Breakdown Spectroscopy in Engines Using Hollow Core Fiber Delivery  

Science Journals Connector (OSTI)

We describe the use of hollow core optical fibers to deliver laser sparks. The sparks are used to ignite engines and to enable air-to-fuel measurements by laser induced breakdown...

Joshi, Sachin; Yalin, Azer P; Dumitrescu, Cosmin; Olcmen, Semih; Puzinauskas, Paul

32

Laser ignition  

Science Journals Connector (OSTI)

Due to their thermodynamic benefits, second-generation spark-ignition engines with gasoline direct injection systems have ... combination of a spray-guided combustion process with laser-induced ignition allows th...

Bernhard Geringer; Dominikus Klawatsch; Josef Graf; Hans Peter Lenz…

2004-03-01T23:59:59.000Z

33

Engineering Peer Review June 5-7, 2001 1 FUSION IGNITION  

E-Print Network [OSTI]

Engineering Peer Review June 5-7, 2001 1 FUSION IGNITION RESEARCH EXPERIMENT (FIRE) Machine Configuration Tom Brown (PPPL) June 5 ­ 7 , 2001 #12;Engineering Peer Review June 5-7, 2001 2 FIRE Configuration approach. Summary. #12;Engineering Peer Review June 5-7, 2001 3 FIRE Configuration Features Double null

34

Mathematical analysis of spark ignition engine operation via the combination of the first and second laws of thermodynamics  

Science Journals Connector (OSTI)

...cycle simulation of the diesel cycle: exergy as a second...Shapiro, H. N. 2000 Fundamentals of engineering thermodynamic...on a turbo-charged diesel engine performance and exergy...spark ignition engine cycle using first and second...

2008-01-01T23:59:59.000Z

35

Particulate Matter Emissions from a Direct Injection Spark Ignition Engine under Cold Fast Idle Conditions for Ethanol-Gasoline Blends  

E-Print Network [OSTI]

The engine out particular matter number (PN) distributions at engine coolant temperature (ECT) of 0° C to 40° C for ethanol/ gasoline blends (E0 to E85) have been measured for a direct-injection spark ignition engine under ...

Dimou, Iason

36

Studies on the effect of turbulence on the performance characteristics of a spark-ignition engine  

Science Journals Connector (OSTI)

Turbulence in a spark-ignition engine significantly influences the performance and emission characteristics. Furthermore, it has been recognised that the presence of turbulence in the inlet manifold of a spark-ignition engine up to a certain level does improve the fuel economy. Hence, in this article, experimental investigations relating to the effect of turbulence generation in the inlet manifold on the overall performance of a spark-ignition engine are reported. Turbulence generators creating 50 and 75 per cent blockage with delta-wing-type blades were used in the inlet manifold of a single-cylinder spark-ignition engine. Subsequently, blade-type turbulence generation were introduced in the same manifold. A comparison between the two cases was made with reference to the overall performance of the engine by measuring the engine power and the turbulence with the help of a hot-wire anemometer. These investigations have shown that blade-type turbulence generators create a significantly larger amount of turbulence, leading to a loss of engine power compared with the delta-wing-shaped generator. However, it is noticed that there is a slight improvement in the performance of the engine when the delta-wing-type of turbulence generator is used compared with the conventional engine.

M.K. Gajendra Babu; R. Sabharwal; P. Sarcar; J.P. Subrahmanyam

1991-01-01T23:59:59.000Z

37

Fuel mixture stratification as a method for improving homogeneous charge compression ignition engine operation  

DOE Patents [OSTI]

A method for slowing the heat-release rate in homogeneous charge compression ignition ("HCCI") engines that allows operation without excessive knock at higher engine loads than are possible with conventional HCCI. This method comprises injecting a fuel charge in a manner that creates a stratified fuel charge in the engine cylinder to provide a range of fuel concentrations in the in-cylinder gases (typically with enough oxygen for complete combustion) using a fuel with two-stage ignition fuel having appropriate cool-flame chemistry so that regions of different fuel concentrations autoignite sequentially.

Dec, John E. (Livermore, CA); Sjoberg, Carl-Magnus G. (Livermore, CA)

2006-10-31T23:59:59.000Z

38

A diesel engine study of conventional and alternative diesel and jet fuels: Ignition and emissions characteristics  

Science Journals Connector (OSTI)

Abstract Measurements of ignition delay, CO and NO emissions, and fuel consumption were carried out in a light-duty single-cylinder direct-injection diesel engine for operation with petroleum and alternative hydroprocessed and Fischer–Tropsch diesel and jet fuels. Ignition measurements carried out for a fixed engine speed and injection timing quantify the decrease in in-cylinder ignition delay with increasing derived cetane number (DCN) over a range of DCN relevant to diesel engine operation (DCN = 40–80) and show no discernible dependence of ignition delay on other fuel properties. Brake specific fuel consumption (BSFC) was found to decrease with increasing DCN with strong correlation due to a reduction in ignition time for fixed-injection-timed operation. Brake specific CO emissions were also found to decrease with increasing DCN due to increased time provided for CO burn out due to earlier ignition. Brake specific NO emissions were found to decrease with increasing hydrogen-to-carbon (H/C) ratio, due to the lower peak combustion temperatures and thermal \\{NOx\\} occurring for fuels with higher H/C.

Sandeep Gowdagiri; Xander M. Cesari; Mingdi Huang; Matthew A. Oehlschlaeger

2014-01-01T23:59:59.000Z

39

ENHANCED IGNITION FOR I.C. ENGINES WITH PREMIXED CHARGE  

E-Print Network [OSTI]

Oper·atEngines- Flame Initiation orInternal Combustion Engines," SAE Paper 760764. Wyczalek, F.an Internal Combustion Engine,'' Combusti and Flame Vol. 31,

Dale, J.D.

2013-01-01T23:59:59.000Z

40

Ignition system  

SciTech Connect (OSTI)

This patent describes an ignition system of an internal combustion engine which consists of: a permanent magnet supported by a rotary member of the engine adapted to rotate in synchronism with a rotary shaft of the engine; a generating coil for generating an electromotive force to produce an electric current as the permanent magnet acts on the generating coil during the rotation of the rotary member; an ignition capacitor charged by the electric current generated by the generating coil; a thyristor caused to turn on by a counter electromotive force generated by the generating coil to thereby cause the ignition capacitor to begin to discharge; and an ignition coil generating a high voltage as the ignition capacitor begins to discharge, to cause a spark discharge to take place in an ignition plug of the internal combustion engine.

Kondo, T.; Ohno, S.

1986-09-16T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

FY2002 Progress Report for Fuels for Advanced Compression Ignition Direct Injection (CIDI) Engines  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fuels for Advanced Compression Fuels for Advanced Compression Ignition Direct Injection (CIDI) Engines Energy Efficiency and Renewable Energy Office of FreedomCAR and Vehicle Technologies Approved by Stephen Goguen November 2002 Fuels for Advanced CIDI Engines FY 2002 Progress Report iii CONTENTS CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii INDEX OF PRIMARY CONTACTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. FUEL/LUBRICANT EFFECTS TESTING ON ENGINE PERFORMANCE . . . . . . . . . 13 A. Oil Consumption Contribution to CIDI PM Emissions during Transient Operation . . . . . . . . . . . . . . . . . . . .13

42

Laser Ignition  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laser Ignition Laser Ignition Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Available for thumbnail of Feynman Center (505) 665-9090 Email Laser Ignition A first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In two embodiments the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion

43

Inevitability of Engine-Out Nox Emissions from Spark-Ignition and Diesel Engines  

SciTech Connect (OSTI)

Internal combustion engines, both spark ignition and Diesel, are dominant types of vehicle power sources and also provide power for other important stationary applications. Overall, these engines are a central part of power generation in modern society. However, these engines, burning hydrocarbon fuels from natural gas to gasoline and Diesel fuel, are also responsible for a great deal of pollutant emissions to the environment, especially oxides of nitrogen (NO{sub x}) and unburned hydrocarbons (UHC). In recent years, pollutant species emissions from internal combustion engines have been the object of steadily more stringent limitations from various governmental agencies. Engine designers have responded by developing engines that reduce emissions to accommodate these tighter limitations. However, as these limits become ever more stringent, the ability of engine design modifications to meet those limits must be questioned. Production of NO{sub x} in internal combustion engines is primarily due to the high temperature extended Zeldovich reaction mechanism: (1) O + N{sub 2} = NO + N; (2) N + O{sub 2} = NO + O; and (3) N + OH = NO + H. The rates of these reactions become significant when combustion temperatures reach or exceed about 2000K. This large temperature dependence, characterized by large activation energies for the rates of the reactions listed here, is a direct result of the need to break apart the tightly bonded oxygen and nitrogen molecules. The strongest bond is the triple bond in the N {triple_bond} N molecule, resulting in an activation energy of about 75 kcal/mole for Reaction (1), which is the principal cause for the large temperature dependence of the extended Zeldovich NO{sub x} mechanism. In most engines, NO{sub x} is therefore produced primarily in the high temperature combustion product gases. Using a reliable kinetic model for NO{sub x} production such as the GRI Mechanism [1] or the Miller-Bowman model [2] with hydrocarbon products at temperatures from 1500K through 2500K, the amounts of NO{sub x} produced at a given residence time in an engine can easily be computed, as shown in Figure 1. Figure 1 depicts how temperatures such as those existing in the combustion zones of heavy-duty engines would produce NO{sub x} emissions. This figure was created assuming that a fuel/air equivalence ratio {phi} of 0.65 was used to heat the combustion air. This equivalence ratio would be similar to that of a heavy-duty lean-burn spark-ignition or diesel engine. At temperatures in the neighborhood of 2000K and residence times between 1-5 milliseconds, which are typical of residence times at these temperatures in engines, the production of NO{sub x} increases dramatically. It is evident from Fig. 1 that product temperatures must remain below approximately 2100K to achieve extremely low NO{sub x} production levels in engines. This conclusion led to a combined experimental and modeling study of product gas temperatures in engine combustion and their influence on emission levels.

Flynn, P F; Hunter, G L; Farrell, L A; Durrett, R P; Akinyemi, O C; Westbrook, C K; Pitz, W J

2000-01-11T23:59:59.000Z

44

Comparative experimental evaluation of performance, combustion and emissions of laser ignition with conventional spark plug in a compressed natural gas fuelled single cylinder engine  

Science Journals Connector (OSTI)

Abstract Laser is emerging as a strong concept for alternative ignition in spark ignition engine. Laser ignition has potential advantages over conventional spark plug ignition. Laser ignition system is free from spark electrodes hence there is no loss of spark energy to the electrodes, which are also free from erosion effect. In addition, there is flexibility in choosing spark location and it offers excellent performance under high in-cylinder pressures. In this paper, performances of laser ignition and conventional spark ignition systems are comparatively evaluated in terms of in-cylinder pressure variation, combustion stability, fuel consumption, power output and exhaust emissions at similar operating conditions of the engine.

Dhananjay Kumar Srivastava; Avinash Kumar Agarwal

2014-01-01T23:59:59.000Z

45

IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM  

SciTech Connect (OSTI)

This report documents a 3-year research program conducted by the Engines & Energy Conversion Laboratory (EECL) at Colorado State University (CSU) to develop micropilot ignition systems for existing pipeline compressor engines. Research activities for the overall program were conducted with the understanding that the efforts are to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. An extensive state-of-art review was conducted to leverage the existing body of knowledge of micropilot ignition with respect to retrofit applications. Additionally, commercially-available fuel injection products were identified and applied to the program where appropriate. This approach will minimize the overall time-to-market requirements, while meeting performance and cost criteria. The objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios under laboratory conditions at the EECL. The primary elements of Micropilot Phase I were to develop a single-cylinder test chamber to study the injection of pilot fuel into a combustion cylinder and to develop, install and test a multi-cylinder micropilot ignition system for a 4-cylinder, natural gas test engine. In all, there were twelve (12) tasks defined and executed to support these two (2) primarily elements in a stepwise fashion. Task-specific approaches and results are documented in this report. The four-cylinder prototype data was encouraging for the micro-pilot ignition technology when compared to spark ignition. The objective for Phase II was to further develop and optimize the micropilot ignition system at the EECL for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase II were to evaluate the results for the 4-cylinder system prototype developed for Phase I, then optimize this system and prepare the technology for the field demonstration phase in Year 3. In all, there were twelve (12) tasks defined and executed to support objectives in a stepwise fashion. The optimized four-cylinder system data demonstrated significant progress compared to Phase I results, as well as traditional spark ignition systems. These laboratory results were enhanced, then verified via a field demonstration project during Phase III of the Micropilot Ignition program. An Implementation Team of qualified engine retrofit service providers was assembled to install the retrofit micropilot ignition system on an engine operated by El Paso Pipeline Group at a compressor station near Window Rock, Arizona. Testing of this demonstration unit showed that the same benefits identified by laboratory testing at CSU, i.e., reduced fuel consumption and exhaust emissions (NOx, THC, CO, and CH2O). Commercialization of the retrofit micropilot ignition technology is awaiting a ''market pull'', which is expected to materialize as the results of the field demonstration become known and accepted. The Implementation Team, comprised of Woodward Governor Company, Enginuity LLC, Hoerbiger Corporation of America, and DigiCon Inc., has direct experience with the technology development and implementation, and stands ready to promote and commercialize the retrofit micropilot ignition system.

Scott Chase; Daniel Olsen; Ted Bestor

2005-05-01T23:59:59.000Z

46

Two stroke homogenous charge compression ignition engine with pulsed air supplier  

DOE Patents [OSTI]

A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

Clarke, John M. (Chillicothe, IL)

2003-08-05T23:59:59.000Z

47

Motion planning for experimental air path control of a variable-valve-timing spark ignition engine  

E-Print Network [OSTI]

to driveability problems) and on the fuel/air ratio (FAR) (leading to pollution peaks). To compensateMotion planning for experimental air path control of a variable-valve-timing spark ignition engine Syste´mes, Mines-ParisTech 60, bd St Michel, 75272 Paris, France a r t i c l e i n f o Article history

48

Explicit-Ready Nonlinear Model Predictive Control for Turbocharged Spark-Ignited Engines  

E-Print Network [OSTI]

Explicit-Ready Nonlinear Model Predictive Control for Turbocharged Spark- Ignited Engines J. El with saturated actuators. In this context, the need for model-based control laws is greater than ever with saturated actuators. In this paper, we evaluate the benefits of a nonlinear model predictive control (NMPC

Paris-Sud XI, Université de

49

Air Charge Control for Turbocharged Spark Ignition Engines with Internal Exhaust Gas Recirculation  

E-Print Network [OSTI]

, the turbocharger wastegate, and the Variable Valve Timing (VVT) system are three actuators in the air path systemAir Charge Control for Turbocharged Spark Ignition Engines with Internal Exhaust Gas Recirculation of transient cylin- der charge control, based on a cycle-averaged mean-value model for a turbocharged spark

Stefanopoulou, Anna

50

IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM-PHASE I  

SciTech Connect (OSTI)

This report documents the first year's effort towards a 3-year program to develop micropilot ignition systems for existing pipeline compressor engines. In essence, all Phase I goals and objectives were met. We intend to proceed with the Phase II research plan, as set forth by the applicable Research Management Plan. The objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase I were to develop a single-cylinder test chamber to study the injection of pilot fuel into a combustion cylinder and to develop, install and test a multi-cylinder micropilot ignition system for a 4-cylinder, natural gas test engine. In all, there were twelve (12) tasks defined and executed to support these two (2) primarily elements in a stepwise fashion. Task-specific approaches and results are documented in this report. Research activities for Micropilot Phase I were conducted with the understanding that the efforts are expected to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. An extensive state-of-art review was conducted to leverage the existing body of knowledge of micropilot ignition with respect to retrofit applications. Additionally, commercially-available fuel injection products were identified and applied to the program where appropriate. This approach will minimize the overall time-to-market requirements, while meeting performance and cost criteria. The four-cylinder prototype data was encouraging for the micro-pilot ignition technology when compared to spark ignition. Initial testing results showed: (1) Brake specific fuel consumption of natural gas was improved from standard spark ignition across the map, 1% at full load and 5% at 70% load. (2) 0% misfires for all points on micropilot ignition. Fuel savings were most likely due to this percent misfire improvement. (3) THC (Total Hydrocarbon) emissions were improved significantly at light load, 38% at 70% load. (4) VOC (Volatile Organic Compounds) emissions were improved above 80% load. (5) Coefficient of Variance for the IMEP (Indicated Mean Effective Pressure) was significantly less at lower loads, 76% less at 70%. These preliminary results will be substantiated and enhanced during Phase II of the Micropilot Ignition program.

Ted Bestor

2003-03-04T23:59:59.000Z

51

Experimental study and modeling of dodecane ignition in a diesel engine  

SciTech Connect (OSTI)

Two experiments have been performed under conditions as close as possible to those existing in a diesel engine. The first is oxidation of n-dodecane in a motored diesel engine running under conditions close to ignition but avoiding it. The progress of chemical reactions is followed by measurements of the global temperature increase {Delta}T of the exhaust gases, and by continuous sampling of the combustion chamber gases, to measure the concentrations of hydroperoxides and molecular hydrogen; about 4.2% of the energy introduced as hydrocarbon is consumed, thus showing significant transformations during the ignition delay of n-dodecane. The location of the maximum concentration of hydroperoxides coincides with the fuel jet`s edge. Tarlike compounds are present in the unburnt dodecane at the engine exhaust. The second experiment is the study of ignition delay of an n-dodecane spray in an oxidation chamber filled with air, between 715 and 760 K and 15 and 25 bar. A reduced mechanism of 32 reactions, with three types of branching due to the species (RO{sub 2}, RO{sub 2}H), (HO{sub 2}, H{sub 2}O{sub 2}), and H, enable one to predict the ignition delay. Computer simulations are made with the KIVA II code. They show good agreement between the experimental and the calculated ignition delays. They also indicate that, during the ignition delay, reactions occur first at the boundary of the fuel spray. A temperature increase of about 100 K takes place at the hottest points, which correspond to concentration maxima of the three branching species. Time-dependent evolutions of average concentrations show that RO{sub 2}H reaches a maximum first, then H{sub 2}O{sub 2}, and lastly the H atom.

Sahetchian, K. [CNRS, Saint-Cyr-l`Ecole (France). Lab. de Mecanique Physique] [CNRS, Saint-Cyr-l`Ecole (France). Lab. de Mecanique Physique; Champoussin, J.C.; Brun, M. [Ecole Centrale de Lyon, Ecully (France). Lab. de Machines Thermiques] [Ecole Centrale de Lyon, Ecully (France). Lab. de Machines Thermiques

1995-11-01T23:59:59.000Z

52

The use of auxiliary ignition devices to improve combustion of low centane-high volatility fuels in a diesel engine  

SciTech Connect (OSTI)

The use of auxiliary ignition devices to improve the combustion of low cetane-high volatility fuels in a Diesel engine is described. Previous combustion with a low cetane-high volatility fuel (with a spark plug located at the periphery of the cylinder) resulted in engine knock at heavy loads and poor engine operation at light loads. In the present investigation, several new ignition devices were used to ignite the fuel in the center of the cylinder, to allow combustion to be controlled by rate of injection. The devices used were an extended spark electrode, a fuel spray deflector, a nozzle glow ring, and a nozzle fuel cage. High speed photography and heat release were used to characterize the ignition and combustion process of the low cetane fuel in conjunction with the ignition devices. Combustion with all of the ignition devices was initiated in the center of the cylinder, significantly reducing engine knock. The use of the auxiliary ignition devices to ignite the fuel in the center of the chamber demonstrated extended operation of the Diesel engine for all of the devices tested.

Stroia, B.L.; Abata. D.L.

1988-01-01T23:59:59.000Z

53

Reactivity Controlled Compression Ignition (RCCI) Combustion on a Multi-Cylinder Light-Duty Diesel Engine  

SciTech Connect (OSTI)

Reactivity controlled compression ignition is a low-temperature combustion technique that has been shown, both in computational fluid dynamics modeling and single-cylinder experiments, to obtain diesel-like efficiency or better with ultra-low nitrogen oxide and soot emissions, while operating primarily on gasoline-like fuels. This paper investigates reactivity controlled compression ignition operation on a four-cylinder light-duty diesel engine with production-viable hardware using conventional gasoline and diesel fuel. Experimental results are presented over a wide speed and load range using a systematic approach for achieving successful steady-state reactivity controlled compression ignition combustion. The results demonstrated diesel-like efficiency or better over the operating range explored with low engine-out nitrogen oxide and soot emissions. A peak brake thermal efficiency of 39.0% was demonstrated for 2600 r/min and 6.9 bar brake mean effective pressure with nitrogen oxide emissions reduced by an order of magnitude compared to conventional diesel combustion operation. Reactivity controlled compression ignition emissions and efficiency results are compared to conventional diesel combustion operation on the same engine.

Curran, Scott [ORNL; Hanson, Reed M [ORNL; Wagner, Robert M [ORNL

2012-01-01T23:59:59.000Z

54

Improving the Efficiency of Spark Ignited, Stoichiometric Natural Gas Engines  

Broader source: Energy.gov [DOE]

This work focused on using camless engine technology to improve the efficiency of a natural gas engine. Late intake close timing and cylinder deactivation were utilized to meet a peak BTE > 40%.

55

Laser Ignition in Internal Combustion Engines- a Novel Approach Based on Advanced Lasers  

Science Journals Connector (OSTI)

Laser ignition with its many potential advantages in comparison to conventional spark plug ignition has been investigated in detail. As ignition source several, to a certain extent...

Weinrotter, Martin; Kopecek, Herbert; Graf, Josef; Klausner, Johann; Herdin, Günther; Wintner, Ernst

56

Investigation of transient plasma ignition for a Pulse Detonation Engine .  

E-Print Network [OSTI]

??Elimination or reduction of auxiliary oxygen use in Pulse Detonation Engines (PDEs) is necessary if the technology is to compete with existing Ramjet systems. This… (more)

Rodriguez, Joel.

2005-01-01T23:59:59.000Z

57

On fuel selection in controlled auto-ignition engines : the link between intake conditions, chemical kinetics, and stratification  

E-Print Network [OSTI]

The objective of this research is to examine the impact fuel selection can have on the high-load limit in a stratified Compression Auto-Ignition (CAI) engine. This was accomplished by first studying the validity of the ...

Maria, Amir Gamal

2012-01-01T23:59:59.000Z

58

Application of Exhaust Gas Fuel Reforming in Compression Ignition Engines Fueled by Diesel and Biodiesel Fuel Mixtures  

Science Journals Connector (OSTI)

In recent years, ester-based oxygenated fuels have been used in compression ignition engines in pure form or as an addition to diesel fuel. ... In hydrocarbon steam reforming (SR), high-temperature steam separates hydrogen from carbon atoms. ...

A. Tsolakis; A. Megaritis; M. L. Wyszynski

2003-09-19T23:59:59.000Z

59

Organic gas emissions from a stoichiometric direct injection spark ignition engine operating on ethanol/gasoline blends  

E-Print Network [OSTI]

The organic gas emissions from a stoichiometric direct injection spark ignition engine operating on ethanol/gasoline blends have been assessed under warmed-up and cold idle conditions. The speciated emissions show that the ...

Kar, Kenneth

60

The effects of cycle-to-cycle variations on nitric oxide (NO) emissions for a spark-ignition engine: Numerical results  

E-Print Network [OSTI]

. To carry out the proposed study, an engine simulation model was used. The simulation determines engine performance and NO emissions as functions of engine operating conditions, engine design parameters, and combustion parameters. An automotive, spark-ignition...

Villarroel, Milivoy

2004-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Crevice volume effect on spark ignition engine efficiency  

E-Print Network [OSTI]

A set of experiments and a simulation study are completed to quantify the effect of the piston crevice on engine efficiency. The simulation study breaks down the loss mechanisms on brake efficiency at different displacement ...

Smith, Patrick M. (Patrick Michael)

2013-01-01T23:59:59.000Z

62

New Methodologies for Analysis of Premixed Charge Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Presentation given at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT).

63

Pressure-wave supercharged spark-ignition engines  

Science Journals Connector (OSTI)

The modern generation of pressure-wave supercharger (PWS) called Hyprex offers a new approach for supercharging gasoline engines. This type of PWS has the potential to replace complex and costly two-stage supe...

Lucas Flückiger; Stephan Tafel; Peter Spring

2006-12-01T23:59:59.000Z

64

Advanced Combustion Operation in a Compression Ignition Engine  

Science Journals Connector (OSTI)

In this study, advanced combustion operating modes were investigated on a DDC/VM Motori 2.5 L, four-cylinder, turbocharged, common rail, direct-injection light-duty diesel engine, with exhaust emission being the main focus. ... This process is based on work from Al-Qurashi et al., who conducted fundamental flame studies that showed that the thermal effect of EGR enhances the oxidative reactivity of diesel soot. ... Heywood, J. B. Internal Combustion Engine Fundamentals; McGraw-Hill Book Company: New York, 1988; p 930. ...

Gregory K. Lilik; José Martín Herreros; André L. Boehman

2008-12-15T23:59:59.000Z

65

Hybrid combustion-premixed gasoline homogeneous charge ignited by injected diesel fuel-4-stroke cycle engines  

SciTech Connect (OSTI)

This paper describes the formation and testing of two hybrid combustion engines, wherein a premixed gasoline homogeneous charge was ignited by a small amount of injected diesel fuel under high compression ratio, by modifying open chamber and prechamber 4-stroke cycle diesel engines. It was found that the premixed gasoline was effective not only for decreasing the fuel consumption but also for reducing the smoke density both in the heavy and over-load regions. The effect of introducing a small amount N/sub 2/ gas for suppressing the diesel knock in the heavy load region also was examined.

Yonetani, H.; Okanishi, N.; Fukutani, I.; Watanabe, E.

1989-01-01T23:59:59.000Z

66

Multi-strike ignition to improve performance, reduce misfiring of large gas engines  

SciTech Connect (OSTI)

New product and application information is now available on the advanced `CPU-2OOO` digital ignition system introduced by Altronic earlier this year for large-bore gas engines and integral compressors. The system is designed to improve performance, reduce misfiring, and be easily retrofitted to existing large-bore engines. including those that are being converted to lean-burn combustion in order to reduce emissions. To do this, the CPU-2OOO system features a selectable multi-striking mode, a selectable energy level and second spark plug cut-off control, a choice of global or individual cylinder timing control, and a high-energy long-duration spark. The 24 Vdc-powered system also offers comprehensive display and communications capabilities, plus system diagnostics and self-test functions. The system uses existing Altronic II-CPU coils, pickups, primary wiring harnesses and other hardware, allowing for easy upgrades of existing II-CPU installations. Also, a detonation avoidance system is being developed as an option for engine protection. Altronic says the field tests have demonstrated the ability of the CPU-20OO system to ignite extra-lean mixtures created when turbochargers are added to engines that previously operated at much richer levels. NO{sub x} emissions have been reduced by as much as 88%, to less than 2.7 g/kWh.

NONE

1995-10-01T23:59:59.000Z

67

End gas autoignition and knock in a spark ignition engine  

SciTech Connect (OSTI)

The paper is concerned with end-gas autoignition, subsequent knock severity and magnitude of induced gas velocity. An optically accessed single cylinder two stroke engine was modified to give complete overhead optical access to the disc-shaped combustion chamber. Flame propagation and end-gas autoignition events were recorded using high speed natural light and schlieren photography; local gas motions, prior to and induced by the knock event, were determined using an oil droplet trajectory technique. Cylinder pressure was synchronously recorded at three positions around the cylinder head; one transducer's output being simultaneously displayed on the film. End gas autoignition generally developed from multiple centers. Autoignition was usually, but not invariably, followed by knock. The severity of knock increased as the onset of autoignition occurred closer behind the top dead centre position; knock was characterized by pressure oscillations, carbon formation and high velocity post-knock gas motions. These phenomena were relatively insensitive to mass fraction unburned at the time of autoignition.

Konig, G.; Sheppard, C.G.W.

1990-01-01T23:59:59.000Z

68

Optimizing the design of a hydrogen engine with pilot diesel fuel ignition  

Science Journals Connector (OSTI)

A diesel engine was converted to dual-fuel hydrogen operation, ignition being started by a 'pilot' quantity of diesel fuel but with 65 to 90% of the energy being supplied as hydrogen. With later injection timing, use of delayed port admission of the gas, and a modified combustion chamber, thermal efficiencies were achieved nearly 15% greater than those for diesel as the sole fuel. A 'solid' water injection technique was used to curb knock under full load conditions when the power output equalled or exceeded that of a similar diesel engine. The indicator diagrams under these conditions closely approach those of the Otto cycle. The development was assisted by computer simulation using a novel self-ignition and flame propagation model. The very fast burning rates obtained with stoichiometric hydrogen-air mixtures show combustion to occur within 5 degrees of crank rotation yet Otto cycle thermal efficiency was not achieved. However, greenhouse gases are shown to be reduced by more than 80%, nitrogen oxides by up to 70%, and exhaust smoke by nearly 80%.

S.M. Lambe; H.C. Watson

1993-01-01T23:59:59.000Z

69

Emission of a compression ignition engine fuelled by diesel and imitated syngas  

Science Journals Connector (OSTI)

Biomass can be converted into a useful source of energy through gasification. The gasification product known as synthesis gas or syngas composition of syngas may fluctuate due to many factors such as operational errors of the gasifier as well as the type of feedstock used or may be due to the feeding rate fluctuation. Therefore it would be difficult to assess the effect of syngas composition and diesel replacement ratio to the emission when combusted in dual fuel syngas – diesel compression ignition engine. In order to overcome this problem controllable composition and conditions of imitated syngas was used in this study by selective three compositions of syngas close to the real conditions. The objective of this study is to determine the exhaust emissions of a compression ignition engine fuelled with diesel and imitated syngas at different compositions and diesel replacement ratios to determine the most appropriate composition of syngas and diesel replacement ratio which will give less emission. The test results on syngas emission are compared with the results of diesel. CO2 and NOX emission level was reduced on syngas dual fuel mode but there were increases in CO and THC emissions throughout all syngas compositions examined due to poor combustion efficiency of dual fuel operation.

2012-01-01T23:59:59.000Z

70

Energetic and exergetic analyses of a variable compression ratio spark ignition gas engine  

Science Journals Connector (OSTI)

Abstract Considering the significance of obtaining higher efficiencies from internal combustion engines (ICE) along with the growing role of natural gas as a fuel, the present work is set to explore the effects of compression ratio (CR hereafter) and air/fuel equivalence ratio (AFER hereafter) on the energy and exergy potentials in a gas-fueled spark ignition internal combustion engine. Experiments are carried out using a single cylinder, port injection, water cooled, variable compression ratio (VCR hereafter), spark ignition engine at a constant engine speed of 2000 rpm. The study involves \\{CRs\\} of 12, 14 and 16 and 10 \\{AFERs\\} between 0.8 and 1.25. Pure methane is utilized for the analysis. In addition, a natural gas blend with the minimum methane content among Iranian gas sources is also tested in order to investigate the effect of real natural gas on findings. The energy analysis involves input fuel power, indicated power and losses due to high temperature of exhaust gases and their unburned content, blow-by and heat loss. The exergy analysis is carried out for availability input and piston, exhaust, and losses availabilities along with destructed entropy. The analysis indicates an increase in the ratio of thermo-mechanical exhaust availability to fuel availability by CR with a maximum near stoichiometry, whereas it is shown that chemical exhaust exergy is not dependent on CR and reduces with AFER. In addition, it is indicated that the ratio of actual cycle to Otto cycle thermal efficiencies is about constant (about 0.784) with changing CR, AFER and CNG fuel used.

A. Javaheri; V. Esfahanian; A. Salavati-Zadeh; M. Darzi

2014-01-01T23:59:59.000Z

71

Performance and Emissions of a Compression Ignition Engine Fueled with Diesel/Oxygenate Blends for Various Fuel Delivery Advance Angles  

Science Journals Connector (OSTI)

State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China ... In the application of pure oxygenated fuels, Fleisch et al.,1 Kapus and Ofner,2 and Sorenson and Mikkelsen3 have studied dimethyl ether (DME) in a modified diesel engine, and their results showed that the engine could achieve ultralow-emission prospects without a fundamental change in combustion systems. ... Although some previous work has revealed the characteristics of diesel/ethanol blends in a compression ignition engine (Satge de Caro et al.,14 Ali et al.15), there, however, is still much work that needs to be done in regard to the application of diesel/methanol blends in compression ignition engines, especially in clarifying the basic combustion and emission. ...

Zuohua Huang; Hongbing Lu; Deming Jiang; Ke Zeng; Bing Liu; Junqiang Zhang; Xibin Wang

2005-02-02T23:59:59.000Z

72

Combustion Characteristics of Diesohol Using Biodiesel as an Additive in a Direct Injection Compression Ignition Engine under Various Compression Ratios  

Science Journals Connector (OSTI)

Studies on combustion characteristics are essential for the optimization of engine design with the use of alternative fuels as compression ignition (CI) engines are basically designed to operate with neat diesel. ... Fleisch et al.,(6) Kapus and Ofner,(7) and Sorenson and Mikkelsen(8) have studied the utilization of pure oxygenated fuels in diesel engines and found that they can achieve ultralow emissions without a fundamental change in the combustion system. ... Engines Research Laboratory in the Mechanical Engineering Department with modern computerized experimental facilities to the international standards. ...

V. Arul Mozhi Selvan; R. B. Anand; M. Udayakumar

2009-10-05T23:59:59.000Z

73

Thermal ignition combustion system  

SciTech Connect (OSTI)

A thermal ignition combustion system adapted for use with an internal combustion engine is described comprising: (a) means for providing ignition chamber walls defining an ignition chamber, the chamber walls being made of a material having a thermal conductivity greater than 20 W/m/sup 0/C. and a specific heat greater than 480J/kg/sup 0/C., the ignition chamber being in constant communication with the main combustion chamber; (b) means for maintaining the temperature of the chamber walls above a threshold temperature capable of causing ignition of a fuel; and (c) means for conducting fuel to the ignition chamber.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

74

Towards the understanding of cyclic variability in a spark ignited engine using multi-cycle LES  

SciTech Connect (OSTI)

Large-Eddy Simulation (LES) has been used to analyze the occurrence and the causes of cycle-to-cycle combustion variations in a spark ignited four-valve single cylinder engine fueled with a homogeneous propane-air mixture. The combustion modeling combines an Eulerian model derived from the RANS AKTIM model that mimics the spark ignition and the Extended Coherent Flame Model (ECFM-LES) that describes the flame propagation. The motion of piston and valves is accounted for using an Arbitrary Eulerian Lagrangian (ALE) technique with body-fitted meshes. The computation covers nine consecutive complete four-stroke cycles following an initialization cycle. The obtained LES results are compared with experimental measurements. Although the number of computed cycles is fairly low, LES is shown to be able to reproduce both quantitatively and qualitatively the cyclic variability observed experimentally. The investigation of the possible causes of variability illustrates the unprecedented possibility LES offers for understanding cycle-to-cycle variations. (author)

Vermorel, O.; Richard, S.; Colin, O.; Angelberger, C.; Benkenida, A. [IFP, 1 and 4 Avenue de Bois-Preau, 92852 Rueil-Malmaison Cedex (France); Veynante, D. [EM2C, CNRS and Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)

2009-08-15T23:59:59.000Z

75

Low-Load Dual-Fuel Compression Ignition (CI) Engine Operation with an On-Board Reformer and a Diesel Oxidation Catalyst: Effects on Engine Performance and Emissions  

Science Journals Connector (OSTI)

Ideally, homogeneous air fuel mixtures ignited spontaneously exhibit less pollutants and can improve engine efficiency compared to standard diesel combustion, which is based on diffusion combustion. ... Although optimization of the injection timing of the in-cylinder DI fuel (e.g., diesel) aims to ignite the mixture and control the start of combustion (SOC) for the different premixed fuel ratios, the fuel ignition timing is complicated and problematic for a dual-fueled engine under a number of engine-operating conditions (e.g., low loads and use of residual gas trapping). ... Deactivation due to coking of a single Ni/Pt-based catalyst is significant, but operation using a platinum-ceria catalyst in line with a Ni-based steam-reforming catalyst allows acceptable efficiencies. ...

A. Tsolakis; R. Torbati; A. Megaritis; A. Abu-Jrai

2009-10-07T23:59:59.000Z

76

Laser-induced ignition and combustion in a SI engine with direct injection  

Science Journals Connector (OSTI)

Laser-induced ignition has shown huge advantages for the combustion ... (KIT) to investigate the potential of the laser-induced ignition. The emphasis was on improving combustion initiation...

Dipl.-Ing. Volker Gross; Dr.-Ing. Heiko Kubach…

2010-07-01T23:59:59.000Z

77

Improving the Efficiency of Spark Ignited, Stoichiometric Natural...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Spark Ignited, Stoichiometric Natural Gas Engines Improving the Efficiency of Spark Ignited, Stoichiometric Natural Gas Engines This work focused on using camless engine technology...

78

Effects of Some Oxygenated Substitutes on Gasoline Properties, Spark Ignition Engine Performance, and Emissions  

Science Journals Connector (OSTI)

It is worthwhile to mention that eucalyptol which can be steam-extracted from eucalyptus leaves has been tested as a co-solvent that prevents alcohol?gasoline blended fuels from phase separation. ... In this table, the compound along with the concentration in the respective base fuel, BRON, and its accuracy as well as relative effectiveness on a molar (RE-M) and a weight (RE-W) basis in comparison with MTBE are shown. ... All the compounds studied exhibited enhanced ignition quality, expressed with their capability to suppress engine knock, performance that can be confirmed from the BRON values of Table 3. From the data in the table, and given the accuracy of the BRON values, which is ±10/x, where x is the w/v % concentration of the compound in the fuel, a decrease of BRON values with the increase of the RON of the base fuel is observed. ...

S. Gouli; E. Lois; S. Stournas

1998-08-12T23:59:59.000Z

80

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

82

The role of neuro-fuzzy modelling as a greening technique, in improving the performance of vehicular spark ignition engine  

Science Journals Connector (OSTI)

The spark ignition engine, by far, is the largest source of motive power in the world. Therefore, continuous endeavours to improve its performance are needed to save in fuel consumption and reduce cost. The main goal of this paper is to develop a neuro-fuzzy model for fuel Injection Time (IT) in order to design a neuro-fuzzy controller for improving the performance of the spark ignition engine. The obtained results showed that the developed neuro-fuzzy model is capable of predicting the fuel IT with a mean squared error less than 0.0072. Furthermore, the power produced by the neuro-fuzzy controller has higher values of about 15-73% than the power produced by the PID controller used in the basic engine. The BSFC is reduced by about 2-5% compared to the PID controller.

Mashhour M. Bani Amer; Yousef S.H. Najjar

2010-01-01T23:59:59.000Z

83

Kinetic Modeling Study of the Ignition Process of Homogeneous Charge Compression Ignition Engine Fueled with Three-Component Diesel Surrogate  

Science Journals Connector (OSTI)

School of Energy & Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China ... Such a computational study is also expected to provide insight into the fundamental understanding of the choice of neat constituents for the surrogate mixture and their relative proportions. ... The present study proposes surrogate models for the nine fuels for advanced combustion engines (FACE) that have been developed for studying low-emission, high-efficiency advanced diesel engine concepts. ...

Gan Xiao; Yusheng Zhang; Jing Lang

2013-02-11T23:59:59.000Z

84

The effects of unburned hydrocarbon recirculation on ignition and combustion during diesel engine cold starts  

Science Journals Connector (OSTI)

Abstract The exhaust gases contain large amounts of unburned hydrocarbons during cranking without combustion. The effects of unburned hydrocarbon recirculation on ignition and combustion during diesel engine cold starts were investigated using both experiments and simulations. Experiments were conducted on a single-cylinder DI (direct injection) diesel engine equipped with a common rail injection system. The amount of unburned hydrocarbon recirculation was jointly controlled by an EGR (exhaust gas recirculation) valve and a back pressure valve. The investigation showed that optimal opening of recirculation control valves allowed the first firing cycle to be advanced from 19 to 6 and reduced the duration of heavy smoke emission (opacity > 50%) by 77%. However, the enhancement to the in-cylinder LTR (low temperature reaction) decreased gradually as the amount of unburned hydrocarbon recirculation increased. An analysis of the chemical kinetics showed that the reaction intermediates present in unburned hydrocarbons, such as ketohydroperoxides, were the most significant factor in enhancing the LTR during non-firing cycles. At the same time, the substantial heat capacity of unburned hydrocarbons suppressed the LTR for higher recirculation rates.

Yi Cui; Haiyong Peng; Kangyao Deng; Lei Shi

2014-01-01T23:59:59.000Z

85

Combustion behavior of a spark ignition engine fueled with synthetic gases derived from biogas  

Science Journals Connector (OSTI)

Abstract Combustion results obtained from a spark ignition engine fueled with two synthetic gases obtained from catalytic decomposition of biogas are presented in this paper. These results are compared with those obtained when the engine was fueled with gasoline, methane and with the biogas from which synthetic gases are extracted. Experimental tests were performed under a wide range of speeds and at three equivalence ratios. Results showed that fractions of hydrogen in synthetic gases increased maximum pressures inside cylinder. Moreover, peak pressures were detected closer to top dead center than methane and biogas. Despite the fraction of diluents in the composition of synthetic gases, high speeds and lean conditions resulted in higher indicated efficiencies than those obtained with gasoline. Moreover, combustion speed and heat release rate were strongly influenced by the proportion of diluents and hydrogen in gaseous blends. CO and CO2 content in the composition of synthetic gases contributed to increase the exhaust concentrations of these pollutants compared with the other fuels, while HC decreased because of the small fraction of methane which remained unburned. Although \\{NOx\\} emissions were mitigated by diluents, like CO2 and air excess, high hydrogen fraction in composition of syngas involved elevated \\{NOx\\} emissions due to the increase in flame temperature that hydrogen produces.

J. Arroyo; F. Moreno; M. Muńoz; C. Monné; N. Bernal

2014-01-01T23:59:59.000Z

86

Fast Ignition  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ignition. The approach being taken by the National Ignition Facility to achieve thermonuclear ignition and burn is called the "central hot spot" scenario. This technique relies...

87

Effect of ambient conditions and fuel properties on homogeneous charge compression ignition engine operation  

E-Print Network [OSTI]

Practical application of Homogeneous Charge Compression Ignition (HCCI) combustion must demonstrate robust responses to variations in environmental conditions. This work examines the impact of ambient conditions and fuel ...

Andreae, Morgan M. (Morgan MacKenzie)

2006-01-01T23:59:59.000Z

88

Characterization of cycle-to-cycle variations in a natural gas spark ignition engine  

Science Journals Connector (OSTI)

Abstract In this work a study of the influence of the fuel/air equivalence ratio and engine rotational speed on the cycle-to-cycle variations in combustion in a natural gas spark ignition engine is presented. The study considers both classic estimators of cyclic dispersion and a new one, based on the burned mass and burning rate. The engine experimental conditions were as follows: Intake pressure 0.5 bar, while fuel/air equivalence ratio was changed from 1.0 to 0.63, and engine rotational speed was varied from 1000 rpm to 2500 rpm. For each equivalence ratio and engine speed, a diagnosis model is used to process the experimentally obtained combustion pressure data in order to provide combustion relevant results such as the mass burning rate at a cycle level. A procedure based on the use of genetic algorithms is used to obtain a very accurate and objective (without human intervention) adjustment of the optimum parameters needed for combustion diagnosis: angular positioning and pressure offset of the pressure register, dynamic compression ratio, and heat transfer coefficients. The model allows making the diagnosis of series of 830 consecutive engine cycles in an automatic way, increasing the objectivity of the combustion diagnosis. The paper focuses on using the values of the mass fraction burned computed from the pressure register and especially on the analysis of the combustion cycle to cycle variation in the natural gas fuelled engine. A new indicator for the study of cycle-to-cycle variations is proposed, i.e. the standard deviation of the mass fraction burning rate. The values of this new indicator are compared with other classic indicators, showing the same general trends. However, a deeper insight is provided on the combustion cyclic variation when the values of the new indicator are plotted as a function of the mass fraction burned, since this allows analyzing the cyclic variation along the combustion development in each cycle from a mass fraction burned of zero to one, with a relevant value at mass fraction burned of 0.5. More important is that the consideration of the dependence of the combustion variables (density, flame front surface, combustion speed) on the mass fraction burned allows ensemble averaging of all registered cycles for each value of mass fraction burned. This permits using the ensemble averaged mass fraction burning rate as an estimator of combustion speed. The analysis of the general trends of cyclic dispersion when engine speed and equivalence ratio are modified (1000, 1750 and 2500 rpm; 0.7, 0.8, 0.9 and 1.0) indicate that cycle-to-cycle variations show, as expected, a strong dependence on the engine rotational speed, increasing the variation with engine rpm. However, when the standard deviation of mass fraction burning rate is plotted as a function of mass fraction burned, there is a linear dependence on engine rpm, but only a very weak dependence on equivalence ratio. This means that the proposed estimator of cyclic dispersion is sensitive to only flow turbulent intensity and not to equivalence ratio.

M. Reyes; F.V. Tinaut; B. Giménez; A. Pérez

2015-01-01T23:59:59.000Z

89

High-Efficiency Clean Combustion Design for Compression Ignition...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

High-Efficiency Clean Combustion Design for Compression Ignition Engines High-Efficiency Clean Combustion Design for Compression Ignition Engines Presentation given at DEER 2006,...

90

Fuel Effects on Ignition and Their Impact on Advanced Combustion...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Ignition and Their Impact on Advanced Combustion Engines Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines Presentation given at DEER 2006, August 20-24,...

91

Premixed ignition behavior of alternative diesel fuel-relevant compounds in a motored engine experiment  

SciTech Connect (OSTI)

A motored engine study using premixed charges of fuel and air at a wide range of diesel-relevant equivalence ratios was performed to investigate autoignition differences among surrogates for conventional diesel fuel, gas-to-liquid (GTL) diesel fuel, and biodiesel, as well as n-heptane. Experiments were performed by delivering a premixed charge of vaporized fuel and air and increasing the compression ratio in a stepwise manner to increase the extent of reaction while monitoring the exhaust composition via Fourier transform infrared (FTIR) spectrometry and collecting condensable exhaust gas for subsequent gas chromatography/mass spectrometry (GC/MS) analysis. Each fuel demonstrated a two-stage ignition process, with a low-temperature heat release (LTHR) event followed by the main combustion, or high-temperature heat release (HTHR). Among the three diesel-relevant fuels, the magnitude of LTHR was highest for GTL diesel, followed by methyl decanoate, and conventional diesel fuel last. FTIR analysis of the exhaust for n-heptane, the conventional diesel surrogate, and the GTL diesel surrogate revealed that LTHR produces high concentrations of aldehydes and CO while producing only negligible amounts of CO{sub 2}. Methyl decanoate differed from the other two-stage ignition fuels only in that there were significant amounts of CO{sub 2} produced during LTHR; this was the result of decarboxylation of the ester group, not the result of oxidation. GC/MS analysis of LTHR exhaust condensate for n-heptane revealed high concentrations of 2,5-heptanedione, a di-ketone that can be closely tied to species in existing autoignition models for n-heptane. GC/MS analysis of the LTHR condensate for conventional diesel fuel and GTL diesel fuel revealed a series of high molecular weight aldehydes and ketones, which were expected, as well as a series of organic acids, which are not commonly reported as products of combustion. The GC/MS analysis of the methyl decanoate exhaust condensate revealed that the aliphatic chain acts similarly to n-paraffins during LTHR, while the ester group remains intact. Thus, although the FTIR data revealed that decarboxylation occurs at significant levels for methyl decanoate, it was concluded that this occurs after the aliphatic chain has been largely consumed by other LTHR reactions. (author)

Szybist, James P.; Boehman, Andre L.; Haworth, Daniel C. [Pennsylvania State University, Fuel Science Program, 405 Academic Activities Building, University Park, PA 16802 (United States); Koga, Hibiki [Honda R and D Company, Ltd., Asaka-shi, Saitama 351-0024 (Japan)

2007-04-15T23:59:59.000Z

92

Performance and exhaust emissions of a two-stroke spark-ignition engine with a direct-injection system  

Science Journals Connector (OSTI)

A direct fuel-injection system has been adapted to a small two-stroke spark-ignition engine to prevent the charge from flowing through the cylinder during the scavenging process. The injection system consists of a jerk-type pump and a single-hole nozzle which supplies gasoline to the cylinder. Engine tests were carried out for comparison with the carburettor version of the same engine. The results show that the direct-injection version can achieve greatly improved thermal efficiency and lower HC and CO emissions without intake throttling. In addition, NOx can be reduced to a much lower level than that of the ordinary four-stroke engine. Heat release analysis and high-speed photography indicate that stratified charge combustion takes place in the direct-injection engine.

Yasuhiro Daisho; Takeshi Saito; Noriaki Ishibe; Mitsuhiro Tsukada; Masashi Yukawa

1991-01-01T23:59:59.000Z

93

Ethanol Blends and Engine Operating Strategy Effects on Light-Duty Spark-Ignition Engine Particle Emissions  

SciTech Connect (OSTI)

Spark ignition (SI) engines with direct injection (DI) fueling can improve fuel economy and vehicle power beyond that of port fuel injection (PFI). Despite this distinct advantage, DI fueling often increases particle emissions such that SI exhaust may be subject to future particle emissions regulations. Challenges in controlling particle emissions arise as engines encounter varied fuel composition such as intermediate ethanol blends. Furthermore, modern engines are operated using unconventional breathing strategies with advanced cam-based variable valve actuation systems. In this study, we investigate particle emissions from a multi-cylinder DI engine operated with three different breathing strategies, fueling strategies and fuels. The breathing strategies are conventional throttled operation, early intake valve closing (EIVC) and late intake valve closing (LIVC); the fueling strategies are single injection DI (sDI), multi-injection DI (mDI), and PFI; and the fuels are emissions certification gasoline, E20 and E85. The results indicate the dominant factor influencing particle number concentration emissions for the sDI and mDI strategies is the fuel injection timing. Overly advanced injection timing results in particle formation due to fuel spray impingement on the piston, and overly retarded injection timing results in particle formation due to poor fuel and air mixing. In addition, fuel type has a significant effect on particle emissions for the DI fueling strategies. Gasoline and E20 fuels generate comparable levels of particle emissions, but E85 produces dramatically lower particle number concentration. The particle emissions for E85 are near the detection limit for the FSN instrument, and particle number emissions are one to two orders of magnitude lower for E85 relative to gasoline and E20. We found PFI fueling produces very low levels of particle emissions under all conditions and is much less sensitive to engine breathing strategy and fuel type than the DI fueling strategies. The particle number-size distributions for PFI fueling are of the same order for all of the breathing strategies and fuel types and are one to two orders lower than for the sDI fuel injection strategy with gasoline and E20. Remarkably, the particle emissions for E85 under the sDI fueling strategy are similar to particle emissions with a PFI fueling strategy. Thus by using E85, the efficiency and power advantages of DI fueling can be gained without generating high particle emissions.

Szybist, James P [ORNL; Youngquist, Adam D [ORNL; Barone, Teresa L [ORNL; Storey, John Morse [ORNL; Moore, Wayne [Delphi; Foster, Matthew [Delphi; Confer, Keith [Delphi

2011-01-01T23:59:59.000Z

94

Combustion Characteristics, Emissions and Heat Release Rate Analysis of a Homogeneous Charge Compression Ignition Engine with Exhaust Gas Recirculation Fuelled with Diesel  

Science Journals Connector (OSTI)

The EGR, a very well-known method for NOx reduction in diesel engines, is also a method in HCCI combustion mode, when fuelled with commercial fuel, to improve engine power, mainly because of the increase of the ignition delay. ... Heywood, J. B. “Internal Combustion Engine Fundamentals”, Ed. McGraw-Hill Book Company, Singapur (Singapur), 1988. ... (Mechanical Engineering Laboratory MITI) “Chemical Kinetic Study of a Cetane Number Enhancing Additive for an LGP DI Diesel Engine,” ...

Miguel Torres García; Francisco J. Jiménez-Espadafor Aguilar; Tomás Sánchez Lencero

2009-04-02T23:59:59.000Z

95

Laser Ignition in Internal Combustion Engines - A Novel Approach Based on Advanced Lasers  

Science Journals Connector (OSTI)

Advantages of laser ignition compared to spark plugs are illustrated. Experiments involving optimized optics and passively Q-switched remotely diode-pumped mJ-Nd:YAG laser have been...

Weinrotter, Martin; Kopecek, Herbert; Wintner, Ernst

96

Analysis of ignition behavior in a turbocharged direct injection dual fuel engine using propane and methane as primary fuels  

SciTech Connect (OSTI)

This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (���© pilot �¢���¼ 0.2-0.6 and ���© overall �¢���¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant ���© pilot (> 0.5), increasing ���© overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing ���© overall (at constant ���© pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

2011-10-05T23:59:59.000Z

97

An investigation of diesel–ignited propane dual fuel combustion in a heavy-duty diesel engine  

Science Journals Connector (OSTI)

Abstract This paper presents a detailed experimental analysis of diesel–ignited propane dual fuel combustion on a 12.9-l, six-cylinder, production heavy-duty diesel engine. Gaseous propane was fumigated upstream of the turbocharger air inlet and ignited using direct injection of diesel sprays. Results are presented for brake mean effective pressures (BMEP) from 5 to 20 bar and different percent energy substituted (PES) by propane at a constant engine speed of 1500 rpm. The effect of propane PES on apparent heat release rates, combustion phasing and duration, fuel conversion and combustion efficiencies, and engine-out emissions of oxides of nitrogen (NOx), smoke, carbon monoxide (CO), and total unburned hydrocarbons (HC) were investigated. Exhaust particle number concentrations and size distributions were also quantified for diesel–ignited propane combustion. With stock engine parameters, the maximum propane PES was limited to 86%, 60%, 33%, and 25% at 5, 10, 15, and 20 bar BMEPs, respectively, either by high maximum pressure rise rates (MPRR) or by excessive HC and CO emissions. With increasing PES, while fuel conversion efficiencies increased slightly at high \\{BMEPs\\} or decreased at low BMEPs, combustion efficiencies uniformly decreased. Also, with increasing PES, \\{NOx\\} and smoke emissions were generally decreased but these reductions were accompanied by higher HC and CO emissions. Exhaust particle number concentrations decreased with increasing PES at low loads but showed the opposite trends at higher loads. At 10 bar BMEP, by adopting a different fueling strategy, the maximum possible propane PES was extended to 80%. Finally, a limited diesel injection timing study was performed to identify the optimal operating conditions for the best efficiency-emissions-MPRR tradeoffs.

Andrew C. Polk; Chad D. Carpenter; Kalyan Kumar Srinivasan; Sundar Rajan Krishnan

2014-01-01T23:59:59.000Z

98

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01T23:59:59.000Z

99

Laser ignition  

DOE Patents [OSTI]

In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2003-01-01T23:59:59.000Z

100

Multi-zone modelling of partially premixed low-temperature combustion in pilot-ignited natural-gas engines  

SciTech Connect (OSTI)

Detailed results from a multi-zone phenomenological simulation of partially premixed advanced-injection low-pilot-ignited natural-gas low-temperature combustion are presented with a focus on early injection timings (the beginning of (pilot) injection (BOI)) and very small diesel quantities (2-3 per cent of total fuel energy). Combining several aspects of diesel and spark ignition engine combustion models, the closed-cycle simulation accounted for diesel autoignition, diesel spray combustion, and natural-gas combustion by premixed turbulent flame propagation. The cylinder contents were divided into an unburned zone, several pilot fuel zones (or 'packets') that modelled diesel evaporation and ignition, a flame zone for natural-gas combustion, and a burned zone. The simulation predicted the onset of ignition, cylinder pressures, and heat release rate profiles satisfactorily over a wide range of BOIs (20-60���° before top dead centre (before TDC)) but especially well at early BOIs. Strong coupling was observed between pilot spray combustion in the packets and premixed turbulent combustion in the flame zone and, therefore, the number of ignition centres (packets) profoundly affected flame combustion. The highest local peak temperatures (greater than 2000 K) were observed in the packets, while the flame zone was much cooler (about 1650 K), indicating that pilot diesel spray combustion is probably the dominant source of engine-out emissions of nitrogen oxide (NO x). Further, the 60���° before TDC BOI yielded the lowest average peak packet temperatures (about 1720 K) compared with the 20���° before TDC BOI (about 2480 K) and 40���° before TDC BOI (about 2700 K). These trends support experimental NO x trends, which showed the lowest NO x emissions for the 60���°, 20���°, and 40���° before TDC BOIs in that order. Parametric studies showed that increasing the intake charge temperature, pilot quantity, and natural-gas equivalence ratio all led to higher peak heat release rates and hotter packets but the pilot quantity and intake temperature affected the potential for NO x formation to a greater extent.

Krishnan, S. R.; Srinivasan, K. K.

2010-06-29T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

State of Development of Laser Ignition  

Science Journals Connector (OSTI)

A holistic optimization of combustion engines with the aim of conserving resources has to include an improvement of the ignition mechanism as well. In the field of spark-ignition combustion engines the developmen...

Prof. Dr.-Ing. Dieter Brüggeman; Dipl.-Ing. Christian Hüttl

2009-03-01T23:59:59.000Z

102

Laser-induced plasma ignition studies in a model scramjet engine  

Science Journals Connector (OSTI)

An experimental investigation of the behavior of laser-induced plasma (LIP) ignition for scramjet inlet injection is presented. The presented results demonstrate for the first time, that LIP can be used to promote the formation of hydroxyl in a hypersonic flow. The temporal evolution of the LIP-ignited region is monitored using the planar laser-induced fluorescence technique on the hydroxyl radical. This study is the first laser spark study in a hypersonic flow, shown to generate combustion products where they would not otherwise occur.

Stefan Brieschenk; Sean O’Byrne; Harald Kleine

2013-01-01T23:59:59.000Z

103

Properties and performance of cotton seed oil–diesel blends as a fuel for compression ignition engines  

Science Journals Connector (OSTI)

This paper presents the evaluation of properties of straight vegetable cotton seed oil (CSO) and its blends with diesel fuel in various proportions to evaluate the performance and emission characteristics of a single cylinder compression ignition (CI) engine at constant speed of 1500 rev ? min . Diesel and CSO oil fuel blends (10% 30% 50% and 70%) were used to conduct engine performance and smoke emission tests at varying loads of 0% 20% 40% 60% 80% and 100% of full load in addition to their straight CSO and diesel fuel. The performance parameters of brake specific energy consumption (BSFC) brake thermal efficiency (BTE) mechanical efficiency (ME) exhaust gas temperature (EGT) and exhaust emission (smoke) were evaluated to find the optimum CSO and diesel fuel blend. From the experimental results the CSO10D90 blend fuel showed 3.7% reduction in BSFC 1.7% increase in BTE 6.7% increase in ME and 21.7% reduction in the smoke emissions in comparison with conventional diesel operated engine. Finally it is concluded that CSO10D90 can be used straight away in CI engines without any major modifications to the engine as it showed good performance and improved emission compared to all other fuels tested for the entire range of engine operation in comparison with diesel.

B. Murali Krishna; J. M. Mallikarjuna

2009-01-01T23:59:59.000Z

104

Numerical study on the combustion and emission characteristics of a methanol/diesel reactivity controlled compression ignition (RCCI) engine  

Science Journals Connector (OSTI)

An improved multi-dimensional model coupled with detailed chemical kinetics mechanism was applied to investigate the combustion and emission characteristics of a methanol/diesel reactivity controlled compression ignition (RCCI) engine. The fuel was supplied separately by directly injecting diesel fuel into cylinder well before top dead center, while premixing methanol through the intake port in the tested methanol/diesel RCCI engine. The effects of mass fraction of premixed methanol, start of injection (SOI) of diesel and initial in-cylinder temperature at intake valve closing (IVC) on engine combustion and emission were investigated in detail. The results show that both methanol mass fraction and SOI have a significant impact on cetane number (CN) distribution, i.e. fuel reactivity distribution, which determines the ignition delay and peak of heat release rate (HRR). Due to larger area with high-temperature region and more homogeneous fuel distribution with increased methanol, and the oxygen atom contained by methanol molecule, all the emissions are reduced with moderate methanol addition. Advanced SOI with high combustion temperature is favorable to hydrocarbon (HC) and soot reduction, yet not to the decrease of nitrogen oxide (NOx) and carbon monoxide (CO) emissions. Both increasing methanol fraction and advancing the SOI are beneficial to improve fuel economy and avoid engine knock. Moreover, it was revealed that the initial temperature must be increased with increased methanol fraction to keep the 50% burn point (CA50) constant, which results in decrease of the equivalent indicated specific fuel consumption (EISFC) and all emissions, except for slight increase in \\{NOx\\} due to the higher burning temperature.

Yaopeng Li; Ming Jia; Yaodong Liu; Maozhao Xie

2013-01-01T23:59:59.000Z

105

The effect of air charge temperature on performance, ignition delay and exhaust emissions of diesel engines using w/o emulsions as fuel  

SciTech Connect (OSTI)

Most of the work performed on the use of water/oil emulsions in diesel engines showed that increasing the water content in the emulsified fuel was effective in reducing NO/sub x/ and soot emissions. Unfortunately, the increase in water content in the emulsified fuel also increases the ignition delay and may cause diesel knock. One way to reduce the ignition delay is to increase the air charge temperature. In this study, the effect of increasing the air charge temperature on ignition delay, performance and exhaust emissions was investigated. The experiments were conducted on a CLR diesel engine using base-line diesel fuel number2 and stabilized macro-emulsions containing 15 percent, 30 percent and 45 percent water by volume.

Afify, E.M.; Korah, N.S.; Dickey, D.W.

1987-01-01T23:59:59.000Z

106

Performance Evaluation of Fuel Blends Containing Croton Oil, Butanol, and Diesel in a Compression Ignition Engine  

Science Journals Connector (OSTI)

† Department of Mechanical Engineering, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa ... (2) The use of vegetable oils in diesel engines is as old as the diesel engine itself. ... The results indicate a general increase in NOx emissions as the load increases at a steady engine speed. ...

Frank Lujaji; Akos Bereczky; Makame Mbarawa

2010-07-15T23:59:59.000Z

107

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME  

SciTech Connect (OSTI)

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an analysis of test results indicates that hydrogen enhanced natural gas HCCI (versus neat natural gas HCCI at comparable stoichiometry) had the following characteristics: • Substantially lower intake temperature needed for stable HCCI combustion • Inconclusive impact on engine BMEP and power produced, • Small reduction in the thermal efficiency of the engine, • Moderate reduction in the unburned hydrocarbons in the exhaust, • Slight increase in NOx emissions in the exhaust, • Slight reduction in CO2 in the exhaust. • Increased knocking at rich stoichiometry The major accomplishments and findings from the project can be summarized as follows: 1. A model was calibrated for accurately predicting heat release rate and peak pressures for HCCI combustion when operating on hydrogen and natural gas blends. 2. A single cylinder research engine was thoroughly mapped to compare performance and emissions for micro-pilot natural gas compression ignition, and HCCI combustion for neat natural gas versus blends of natural gas and hydrogen.

Pratapas, John; Mather, Daniel; Kozlovsky, Anton

2013-03-31T23:59:59.000Z

108

Numerical Simulation of Combustion Processes in Homogeneous and Stratified Charge Spark Ignition Engines  

Science Journals Connector (OSTI)

A three-dimensional simulation technique for stratified combustion process in direct injection gasoline engines is developed....

Hiroshi Miyagawa; Yoshihiro Nomura; Makoto Koike

2001-01-01T23:59:59.000Z

109

Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine  

SciTech Connect (OSTI)

A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO{sub x} emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO{sub x} emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO{sub x} emissions could meet the 2004 Tier II emissions standards with 25%-oxygen-content air.

Ng, H.K.; Sekar, R.R.

1994-04-01T23:59:59.000Z

110

Compression ignition engine performance and emission evaluation of industrial oilseed biofuel feedstocks camelina, carinata, and pennycress across three fuel pathways  

Science Journals Connector (OSTI)

Abstract Industrial oilseeds camelina (Camelina sativa L.), carinata (Brassica carinata), and pennycress (Thlaspi arvense L.) offer great potential as biofuel feedstocks due to their non-food nature and positive agronomic attributes. This research focused on compression ignition (CI) engine performance and emissions of these industrial oilseeds as compared to both traditional feedstocks and petroleum diesel. A John Deere 4.5 L test engine was used to evaluate these oils using three fuel pathways (triglyceride blends, biodiesel, and renewable diesel). This engine research represents the first direct comparison of these new biofuel feedstocks to each other and to conventional sources. For some industrial oilseed feedstock and fuel pathway combinations, this study also represents the first engine performance data available. The results were promising, with camelina, carinata, and pennycress engine performance very similar to the traditional oils for each fuel pathway. Fuel consumption, thermal efficiency, and emissions were all were typical as compared to traditional oilseed feedstocks. Average brake specific fuel consumption (bsfc) for the industrial oilseed biofuels was within ±1.3% of the conventional oilseed biofuels for each fuel type. Initial research with triglyceride blends (TGB), formed by blending straight vegetable oil with gasoline, indicate it may be an ideal fuel pathway for farm-scale fuel production, and was compatible with a direct injection CI engine without modification. TGB had lower fuel consumption and a higher thermal efficiency than biodiesel for each feedstock tested. For several categories, TGB performed similar to petroleum diesel. TGB volumetric bsfc was only 1.9% higher than the petroleum runs. TGB combustion characteristics were similar to biodiesel. Biodiesel runs had several emission benefits such as reductions in carbon monoxide (CO), non-methane hydrocarbons (NMHC), volatile organic compounds (VOCs), and formaldehyde (CH20) emissions as compared to TGB runs. The renewable diesels had petroleum-like engine performance and combustion characteristics, while still maintaining some of the benefits of biodiesel such as reduced CO emissions. Nitrogen oxides (NOx) emissions were also 6% lower for renewable diesel runs than petroleum. Both crude and refined oil was used as feedstock, and did not significantly affect engine performance or emissions in a modern CI engine.

A.C. Drenth; D.B. Olsen; P.E. Cabot; J.J. Johnson

2014-01-01T23:59:59.000Z

111

Performance of a spark ignition engine fueled with methanol or methanol-gasoline blends  

SciTech Connect (OSTI)

Engine torque and specific energy consumption of an automotive engine were studied under steady state condition using gasoline, methanol gasoline blends and straight methanol as fuel. At first the engine was run without any modification. Next the diameters of metering orifices in carburetor were modified to give the same excess air factor regardless of fuel type under each fixed engine operating condition. Finally the engine was run with 15% mixture methanol in gasoline by volume using the carburetor modified to have approximately 10% larger fuel flow area than the production carburetor. From the results of this study the effects of using methanol on engine torque and specific energy consumption can be explained on the basis of change in stoichiometry caused by the use of methanol.

You, B.C.

1983-11-01T23:59:59.000Z

112

Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark Ignition Engines  

Broader source: Energy.gov [DOE]

Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010.

113

Effect of Bioethanol Blended Diesel Fuel and Engine Load on Spray, Combustion, and Emissions Characteristics in a Compression Ignition Engine  

Science Journals Connector (OSTI)

Yan et al.(8) investigated the combustion and emission characteristics of diesel engines fueled with ethanol–diesel blended fuel in a single cylinder diesel engine. ... Figure 11 shows the indicated specific fuel consumption (ISFC) characteristics of diesel–bioethanol blended fuels at various engine loads. ... Tests on the engine fuelled with diesel only were made, and the performance evaluated to form a basis for comparison for those of ethanol-diesel dual fuelling. ...

Su Han Park; In Mo Youn; Yunsung Lim; Chang Sik Lee

2012-07-03T23:59:59.000Z

114

Sources and characteristics of oil consumption in a spark-ignition engine  

E-Print Network [OSTI]

(cont.) At low load, oil flowing past by the piston was found to be the major consumption source, while the contributions of oil evaporation and of blowby entrainment became more significant with increasing engine load. ...

Yilmaz, Ertan, 1970-

2003-01-01T23:59:59.000Z

115

Application of semi-direct injection for spark-ignition engine  

Science Journals Connector (OSTI)

This paper proposes an application of a motorcycle engine lean-burn system for improving engine efficiency and reducing exhaust emissions. This Semi-Direct Injection (SDI) system consists of a high swirl charge, injection during intake-valve opening, and air-assisted fuel injection. The fuel enters the cylinder directly through the intake valve near the middle intake stroke for a richer mixture around the spark plug. A 125 cc, 4-valve, Port-Fuel-Injection (PFI) engine was retrofitted by designing a control plate to enhance the swirl. The swirl ratio was increased to 3.8 and the lean limit was extended to 1.7 of lambda (excess air ratio). The engine was tested at the low-load region, which includes most operation points of the ECE-40 driving cycle. A complete engine performance map was conducted for comparison between SDI and original PFI engines. The results show that Brake-Specific Fuel Consumption (BSFC) decreased by 11.3%. Brake-specific exhaust emissions of NOx and CO decreased by 32.0% and 92.9%, respectively. The HC emission increased by 47.7%.

Yuh-Yih Wu; Bo-Chiuan Chen; Anh-Trung Tran

2010-01-01T23:59:59.000Z

116

Investigation on Firing Behavior of the Spark-Ignition Engine Fueled with Methanol, Liquefied Petroleum Gas (LPG), and Methanol/LPG During Cold Start  

Science Journals Connector (OSTI)

It can be produced from synthesis gas (a mixture of carbon monoxide (CO) and hydrogen) that is formed by steam reforming of natural gas, by gasification of coal, or from biomass, all of which are available in abundance or renewable. ... Liguang et al.,(16) based on cycle-by-cycle control strategy on an EFI (electronic fuel injection) LPG engine, studied how to control the ignition cycle and performed both single-cycle and multicycle tests. ...

Changming Gong; Baoqing Deng; Shu Wang; Yan Su; Qing Gao; Xunjun Liu

2008-10-04T23:59:59.000Z

117

Catalytic converter applications for two stroke, spark-ignited marine engines  

SciTech Connect (OSTI)

When catalytic converters are used for cleansing of exhaust gas from two-stroke marine engines, new issues must be brought up in combination with prior technology. Therefore, a study was made of V6, 2600cc engine having a large volume of hydrocarbon emissions with respect to three issues: (1) To what degree seawater effects catalytic converter performance and possible countermeasures; (2) Effects attained on cleansing level and catalyst temperature; (3) Finding abatement levels for catalyst deterioration and exhaust emission output in the marine mode. It was found that physical adsorption was a significant factor in catalytic degradation resulting from direct contact with seawater. The cleansing levels obtained when a marine engine is equipped with a catalyst converter were found by clarifying the extent of effects of catalyst volume, performance and temperature. The reduction obtained in exhaust emission allowing for a deterioration factor, is shown in a catalytic converter heated to the maximum temperature of 960 C.

Fujimoto, Hiroaki; Isogawa, Atsushi; Matsumoto, Naoto

1995-12-31T23:59:59.000Z

118

Efficiency and emissions of a spark ignition engine fueled with synthetic gases obtained from catalytic decomposition of biogas  

Science Journals Connector (OSTI)

This paper presents the results of the tests developed in a naturally aspirated spark ignition engine, intended for installation in vehicles, fueled with synthetic gases obtained from catalytic decomposition of biogas. The experimental tests were carried out at three equivalence ratios and different speeds and loads. Two synthetic blends were used and the results were compared with those of gasoline and methane. Efficiency and emissions were calculated for the different fuels under the same operation conditions and it was found that at lean equivalence ratios, brake thermal efficiency with synthetic gases approached to the traditional fuels and even improved it at ? = 0.7. BSCO2 emissions increased due to the CO2 content of the gaseous blends. While CO increased at stoichiometric conditions, it decreased at lean conditions because the H2 contained in synthetic gases improved combustion at these conditions. BSHC measured were very low with synthetic gases because of the low content of methane in blends. The change in the fraction of H2 and CO2 of the synthetic blends led to quite different results in BSNOx. Syngas 1 \\{BSNOx\\} emissions were the lowest of all fuels, while syngas 2 \\{BSNOx\\} were the highest because of its high H2 fraction.

J. Arroyo; F. Moreno; M. Muńoz; C. Monné

2013-01-01T23:59:59.000Z

119

Feasibility study of a 6V-92TA homogeneous auto-ignited two-stroke (HAT) compressed-natural-gas-engine. Topical report, August 1989-May 1990  

SciTech Connect (OSTI)

The objective of the project was to modify a two-stroke 6V-92TA diesel engine to operate on natural gas using a simple system with gas addition to the compressor inlet and a spark plug for cold start and non-autoignition engine operation. The engine was to be operated at most speed-load conditions by autoignition of the premixed gas-air mixture. This concept is referred to as the Homogeneous Auto-Ignited Two-Stroke (HAT). Autoignition of carbureted natural gas was achieved at various loads and speeds in a 6V-92TA engine modified for operating on natural gas with the HAT concept. However, HAT engine operation up to 277 hp at 2100 rpm (diesel coach rating) was not achieved because early ignition in some cylinders caused knock and excessive heat transfer. Instead, the engine was operated up to 226 hp (767 N.m) at 2100 rpm, 181 hp (780 N.m) at 1650 rpm, 130 hp (773 N.m) at 1200 rpm, and 34 hp (368 N.m) at 650 rpm. Maximum brake thermal efficiency measured was 33.4% at 2100 rpm/219 hp. The corrected efficiency (to compensate for the unburned natural gas lost during the scavenging process) was higher than this. Steady-state emissions show very low NOx, total unburned HC lower than expected and reasonable CO levels. The lean air-fuel mixture and unburned exhaust gases in the cylinder resulted in very low NOx emissions.

Kakwani, R.M.; Winsor, R.E.

1990-08-01T23:59:59.000Z

120

Spark ignition engine control strategies for minimising cold start fuel consumption under cumulative tailpipe emissions constraints  

Science Journals Connector (OSTI)

Abstract This paper proposes a methodology for minimising the fuel consumption of a gasoline fuelled vehicle during cold starting. It first takes a validated dynamic model of an engine and its aftertreatment reported in a previous study (Andrianov, Brear, & Manzie, 2012) to identify optimised engine control strategies using iterative dynamic programming. This is demonstrated on a family of optimisation problems, in which fuel consumption is minimised subject to different tailpipe emissions constraints and exhaust system designs. Potential benefits of using multi-parameter optimisation, involving spark timing, air–fuel ratio and cam timing, are quantified. Single switching control policies are then proposed that perform close to the optimised strategies obtained from the dynamic programming but which require far less computational effort.

D.I. Andrianov; C. Manzie; M.J. Brear

2013-01-01T23:59:59.000Z

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121

Effects of primary breakup modeling on spray and combustion characteristics of compression ignition engines  

SciTech Connect (OSTI)

Injector flow dynamics and primary breakup processes are known to play a pivotal role in determining combustion and emissions in diesel engines. In the present study, we examine the effects of primary breakup modeling on the spray and combustion characteristics under diesel engine conditions. The commonly used KH model, which considers the aerodynamically induced breakup based on the Kelvin-Helmholtz instability, is modified to include the effects of cavitation and turbulence generated inside the injector. The KH model and the new (KH-ACT) model are extensively evaluated by performing 3-D time-dependent simulations with detailed chemistry under diesel engine conditions. Results indicate that the inclusion of cavitation and turbulence enhances primary breakup, leading to smaller droplet sizes, decrease in liquid penetration, and increase in the radial dispersion of spray. Predictions are compared with measurements for non-evaporating and evaporating sprays, as well as with flame measurements. While both the models are able to reproduce the experimentally observed global spray and combustion characteristics, predictions using the KH-ACT model exhibit closer agreement with measurements in terms of liquid penetration, cone angle, spray axial velocity, and liquid mass distribution for non-evaporating sprays. Similarly, the KH-ACT model leads to better agreement with respect to the liquid length and vapor penetration distance for evaporating sprays, and with respect to the flame lift-off location for combusting sprays. The improved agreement is attributed to the ability of the new model to account for the effects of turbulence and cavitation generated inside the injector, which enhance the primary breakup. Results further indicate that the combustion under diesel engine conditions is characterized by a double-flame structure with a rich premixed reaction zone near the flame stabilization region and a non-premixed reaction zone further downstream. This flame structure is consistent with the Dec's model for diesel engine combustion (Dec, 1997), and well captured by a newly developed flame index based on the scalar product of CO and O{sub 2} mass fraction gradients. (author)

Som, S.; Aggarwal, S.K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States)

2010-06-15T23:59:59.000Z

122

Methylal and Methylal-Diesel Blended Fuels from Use In Compression-Ignition Engines  

SciTech Connect (OSTI)

Gas-to-liquids catalytic conversion technologies show promise for liberating stranded natural gas reserves and for achieving energy diversity worldwide. Some gas-to-liquids products are used as transportation fuels and as blendstocks for upgrading crude derived fuels. Methylal (CH{sub 3}-O-CH{sub 2}-O-CH{sub 3}) also known as dimethoxymethane or DMM, is a gas-to-liquid chemical that has been evaluated for use as a diesel fuel component. Methylal contains 42% oxygen by weight and is soluble in diesel fuel. The physical and chemical properties of neat methylal and for blends of methylal in conventional diesel fuel are presented. Methylal was found to be more volatile than diesel fuel, and special precautions for distribution and fuel tank storage are discussed. Steady state engine tests were also performed using an unmodified Cummins 85.9 turbocharged diesel engine to examine the effect of methylal blend concentration on performance and emissions. Substantial reductions of particulate matter emissions h ave been demonstrated 3r IO to 30% blends of methylal in diesel fuel. This research indicates that methylal may be an effective blendstock for diesel fuel provided design changes are made to vehicle fuel handling systems.

Keith D. Vertin; James M. Ohi; David W. Naegeli; Kenneth H. Childress; Gary P. Hagen; Chris I. McCarthy; Adelbert S. Cheng; Robert W. Dibble

1999-05-05T23:59:59.000Z

123

Impact of N2 dilution on combustion and emissions in a spark ignition CNG engine  

Science Journals Connector (OSTI)

Abstract In order to reduce \\{NOx\\} (nitrogen oxides) emissions, N2 (nitrogen) was introduced as dilution gas to dilute mixture with a specially-designed injection device. The impacts of varying N2 DR (dilution ratio) on the combustion and the exhaust emissions were investigated, including engine heat release rate, indicator diagram, NOx, CO (carbon monoxide), THC (total hydrocarbon) emissions and so on. For this study, a modified 6.6 L CNG (compressed natural gas) engine was tested and N2 was injected into the end of intake manifold by a specially-designed device. The results showed that N2 dilution has a significant influence on the combustion and the exhaust emissions. With the rise of N2 DR, the maximum of pressure in cylinder and the maximum of heat release rate exhibited decrease trends, the centre of heat release curve showed a moving backward tendency. Higher N2 DR exhibited lower \\{NOx\\} (17–81%) emissions, but higher emissions of THC (3–78%) and CO (1–28%). The change of BSFC (brake specific fuel consumption) can be ignored with N2 DR no more than 167%. Satisfactory results can be obtained, with lower \\{NOx\\} (31%) emissions, lower BSFC (0.5%), and relatively higher THC (6%) and CO (1%) emissions, when N2 DR is 67%.

Zhongshu Wang; Hongbin Zuo; Zhongchang Liu; Weifeng Li; Huili Dou

2014-01-01T23:59:59.000Z

124

Comparison of Conventional Diesel and Reactivity Controlled Compression Ignition (RCCI) Combustion in a Light-Duty Engine  

Broader source: Energy.gov [DOE]

CFD modeling was used to compare conventional diesel and dual-fuel Reactivity Controlled Compression Ignition combustion at US Tier 2 Bin 5 NOx levels, while accounting for Diesel Exhaust Fluid needed to meet NOx constraints with aftertreatment.

125

A Numerical Study of Transient Ignition in a Counter ow Nonpremixed Methane-Air Flame using  

E-Print Network [OSTI]

of hydrocarbon fuels, for example in diesel engines or in knocking of spark-ignition engines. Such processes

Petzold, Linda R.

126

Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine  

SciTech Connect (OSTI)

An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly injected fuel unlike other low temperature combustion (LTC) strategies.

Cho, Kukwon [ORNL] [ORNL; Curran, Scott [ORNL] [ORNL; Prikhodko, Vitaly Y [ORNL] [ORNL; Sluder, Scott [ORNL] [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL] [ORNL

2011-01-01T23:59:59.000Z

127

Ignition Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ignition Experiments The goal of many NIF experiments is to create a self-sustaining "burn" of fusion fuel (the hydrogen isotopes deuterium and tritium) that produces as much or...

128

Experimental study on combustion characteristics of a spark-ignition engine fueled with natural gas–hydrogen blends combining with EGR  

Science Journals Connector (OSTI)

An experimental study on the effect of hydrogen fraction and EGR rate on the combustion characteristics of a spark-ignition engine fueled with natural gas–hydrogen blends was investigated. The results show that flame development duration, rapid combustion duration and total combustion duration are increased with the increase of EGR rate and decreased with the increase of hydrogen fraction in the blends. Hydrogen addition shows larger influence on flame development duration than that on rapid combustion duration. The coefficient of variation of the indicated mean effective pressure increases with the increase of EGR rate. And hydrogen addition into natural gas decreases the coefficient of variation of the indicated mean effective pressure, and this effectiveness becomes more obviously at high EGR rate. Engine fueled with natural gas–hydrogen blends combining with proper EGR rate can realize the stable low temperature combustion in gas engine.

Erjiang Hu; Zuohua Huang; Bing Liu; Jianjun Zheng; Xiaolei Gu

2009-01-01T23:59:59.000Z

129

DRIVE CYCLE EFFICIENCY AND EMISSIONS ESTIMATES FOR REACTIVITY CONTROLLED COMPRESSION IGNITION IN A MULTI-CYLINDER LIGHT-DUTY DIESEL ENGINE  

SciTech Connect (OSTI)

In-cylinder blending of gasoline and diesel to achieve Reactivity Controlled Compression Ignition (RCCI) has been shown to reduce NOx and PM emissions while maintaining or improving brake thermal efficiency as compared to conventional diesel combustion (CDC). The RCCI concept has an advantage over many advanced combustion strategies in that by varying both the percent of premixed gasoline and EGR rate, stable combustion can be extended over more of the light-duty drive cycle load range. Changing the percent premixed gasoline changes the fuel reactivity stratification in the cylinder providing further control of combustion phasing and pressure rise rate than the use of EGR alone. This paper examines the combustion and emissions performance of light-duty diesel engine using direct injected diesel fuel and port injected gasoline to carry out RCCI for steady-state engine conditions which are consistent with a light-duty drive cycle. A GM 1.9L four-cylinder engine with the stock compression ratio of 17.5:1, common rail diesel injection system, high-pressure EGR system and variable geometry turbocharger was modified to allow for port fuel injection with gasoline. Engine-out emissions, engine performance and combustion behavior for RCCI operation is compared against both CDC and a premixed charge compression ignition (PCCI) strategy which relies on high levels of EGR dilution. The effect of percent of premixed gasoline, EGR rate, boost level, intake mixture temperature, combustion phasing and pressure rise rate is investigated for RCCI combustion for the light-duty modal points. Engine-out emissions of NOx and PM were found to be considerably lower for RCCI operation as compared to CDC and PCCI, while HC and CO emissions were higher. Brake thermal efficiency was similar or higher for many of the modal conditions for RCCI operation. The emissions results are used to estimate hot-start FTP-75 emissions levels with RCCI and are compared against CDC and PCCI modes.

Curran, Scott [ORNL; Briggs, Thomas E [ORNL; Cho, Kukwon [ORNL; Wagner, Robert M [ORNL

2011-01-01T23:59:59.000Z

130

Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing  

E-Print Network [OSTI]

Ford Motor Company, “Diesel Engine Aftertreatment: How FordNational Laboratory, “Engine Combustion Network”, http://High Power Output without Engine Knock and with Ultra-Low

Saxena, Samveg

2011-01-01T23:59:59.000Z

131

Effect of syngas composition on combustion and exhaust emission characteristics in a pilot-ignited dual-fuel engine operated in PREMIER combustion mode  

Science Journals Connector (OSTI)

The objective of this study was to investigate the performance and emissions of a pilot-ignited, supercharged, dual-fuel engine powered by different types of syngas at various equivalence ratios. It was found that if certain operating conditions were maintained, conventional engine combustion could be transformed into combustion with two-stage heat release. This mode of combustion has been investigated in previous studies with natural gas, and has been given the name \\{PREmixed\\} Mixture Ignition in the End-gas Region (PREMIER) combustion. PREMIER combustion begins as premixed flame propagation, and then, because of mixture autoignition in the end-gas region, ahead of the propagating flame front, a transition occurs, with a rapid increase in the heat release rate. It was determined that the mass of fuel burned during the second stage affected the rate of maximum pressure rise. As the fuel mass fraction burned during the second stage increased, the rate of maximum pressure rise also increased, with a gradual decrease in the delay between the first increase in the heat release rate following pilot fuel injection and the point when the transition to the second stage occurred. The H2 and CO2 content of syngas affected the engine performance and emissions. Increased H2 content led to higher combustion temperatures and efficiency, lower CO and HC emissions, but higher \\{NOx\\} emissions. Increased CO2 content influenced performance and emissions only when it reached a certain level. In the most recent studies, the mean combustion temperature, indicated thermal efficiency, and \\{NOx\\} emissions decreased only when the CO2 content of the syngas increased to 34%. PREMIER combustion did not have a major effect on engine cycle-to-cycle variation. The coefficient of variation of the indicated mean effective pressure (COVIMEP) was less than 4% for all types of fuel at various equivalence ratios, indicating that the combustion was within the stability range for engine operation.

Ulugbek Azimov; Eiji Tomita; Nobuyuki Kawahara; Yuji Harada

2011-01-01T23:59:59.000Z

132

Syngas (H2/CO) in a spark-ignition direct-injection engine. Part 1: Combustion, performance and emissions comparison with CNG  

Science Journals Connector (OSTI)

Abstract The combustion, performance, and emissions of syngas (H2/CO) in a four-stroke, direct-injection, spark-ignition engine were experimentally investigated. The engine was operated at various speeds, ranging from 1500 to 2400 rev/min, with the throttle being held in the wide-open position. The start of fuel injection was fixed at 180° before the top dead center, and the ignition advance was set at the maximal brake torque. The air/fuel ratio was varied from the technically possible lowest excess air ratio (?) to lean operation limits. The results indicated that a wider air/fuel operating ratio is possible with syngas with a very low coefficient of variation. The syngas produced a higher in-cylinder peak pressure and heat-release rate peak and faster combustion than for CNG. However, CNG produced a higher brake thermal efficiency (BTE) and lower brake specific fuel consumption (BSFC). The BTE and BSFC of the syngas were on par to those of CNG at higher speeds. For the syngas, the total hydrocarbon emission was negligible at all load conditions, and the carbon monoxide emission was negligible at higher loads and increased under lower load conditions. However, the emission of nitrogen oxides was higher at higher loads with syngas.

Ftwi Yohaness Hagos; A. Rashid A. Aziz; Shaharin A. Sulaiman

2014-01-01T23:59:59.000Z

133

Effect of the use of olive–pomace oil biodiesel/diesel fuel blends in a compression ignition engine: Preliminary exergy analysis  

Science Journals Connector (OSTI)

Abstract Although biodiesel is among the most studied biofuels for diesel engines, it is usually produced from edible oils, which gives way to controversy between the use of land for fuel and food. For this reason, residues like olive–pomace oil are considered alternative raw materials to produce biodiesel that do not compete with the food industry. To gain knowledge about the implications of its use, olive–pomace oil methyl ester, straight and blended with diesel fuel, was evaluated as fuel in a direct injection diesel engine Perkins AD 3-152 and compared to the use of fossil diesel fuel. Performance curves were analyzed at full load and different speed settings. To perform the exergy balance of the tested fuels, the operating conditions corresponding to maximum engine power values were considered. It was found that the tested fuels offer similar performance parameters. When straight biodiesel was used instead of diesel fuel, maximum engine power decreased to 5.6%, while fuel consumption increased up to 7%. However, taking into consideration the Second Law of the Thermodynamics, the exergy efficiency and unitary exergetic cost reached during the operation of the engine under maximum power condition for the assessed fuels do not display significant differences. Based on the exergy results, it may be concluded that olive–pomace oil biodiesel and its blends with diesel fuel may substitute the use of diesel fuel in compression ignition engines without any exergy cost increment.

I. López; C.E. Quintana; J.J. Ruiz; F. Cruz-Peragón; M.P. Dorado

2014-01-01T23:59:59.000Z

134

Performance and Emissions Characteristics of Bio-Diesel (B100)-Ignited Methane and Propane Combustion in a Four Cylinder Turbocharged Compression Ignition Engine  

SciTech Connect (OSTI)

Different combustion strategies and fuel sources are needed to deal with increasing fuel efficiency demands and emission restrictions. One possible strategy is dual fueling using readily available resources. Propane and natural gas are readily available with the current infrastructure and biodiesel is growing in popularity as a renewable fuel. This paper presents experimental results from dual fuel combustion of methane (as a surrogate for natural gas) and propane as primary fuels with biodiesel pilots in a 1.9 liter, turbocharged, 4 cylinder diesel engine at 1800 rev/min. Experiments were performed with different percentage energy substitutions (PES) of propane and methane and at different brake mean effective pressures (BMEP/bmep). Brake thermal efficiency (BTE) and emissions (NOx, HC, CO, CO2, O2 and smoke) were also measured. Maximum PES levels for B100-methane dual fuelling were limited to 70% at 2.5 bar bmep and 48% at 10 bar bmep, and corresponding values for B100-propane dual fuelling were 64% and 43%, respectively. Maximum PES was limited by misfire at 2.5 bar bmep and the onset of engine knock at 10 bar bmep. Dual fuel BTEs approached straight B100 values at 10 bar bmep while they were significantly lower than B100 values at 2.5 bar bmep. In general dual fuelling was beneficial in reducing NOx and smoke emissions by 33% and 50%, respectively from baseline B100 levels; however, both CO and THC emissions were significantly higher than baseline B100 levels at all PES and loads.

Shoemaker, N. T.; Gibson, C. M.; Polk, A. C.; Krishnan, S. R.; Srinivasan, K. K.

2011-10-05T23:59:59.000Z

135

Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 1. Engine Load Range and Downsize Downspeed Opportunity  

SciTech Connect (OSTI)

The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine was used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to 87 AKI, up to 20 bar IMEPg (indicated mean effective pressure gross) at = 1. EGR provided thermodynamic advantages and was a key enabler for increasing engine efficiency for all fuel types. However, with E30, EGR was less useful for knock mitigation than gasoline or IB24. Torque densities with E30 with 15% EGR at = 1 operation were similar or better than a modern EURO IV calibration turbo-diesel engine. The results of the present study suggest that it could be possible to implement a 40% downsize + downspeed configuration (1.2 L engine) into a representative midsize sedan. For example, for a midsize sedan at a 65 miles/h cruise, an estimated fuel consumption of 43.9 miles per gallon (MPG) (engine out 102 g-CO2/km) could be achieved with similar reserve power to a 2.0 L engine with 87AKI (38.6 MPG, engine out 135 g-CO2/km). Data suggest that, with midlevel alcohol gasoline blends, engine and vehicle optimization can offset the reduced fuel energy content of alcohol gasoline blends and likely reduce vehicle fuel consumption and tailpipe CO2 emissions.

Splitter, Derek A [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL

2013-01-01T23:59:59.000Z

136

Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing  

E-Print Network [OSTI]

Experimental study of biogas combustion characteristics andthe operation range of a biogas HCCI engine for powerOperating Conditions in a Biogas Fueled HCCI Engine for

Saxena, Samveg

2011-01-01T23:59:59.000Z

137

Part-load performance and emissions of a spark ignition engine fueled with RON95 and RON97 gasoline: Technical viewpoint on Malaysia’s fuel price debate  

Science Journals Connector (OSTI)

Abstract Due to world crude oil price hike in the recent years, many countries have experienced increase in gasoline price. In Malaysia, where gasoline are sold in two grades; RON95 and RON97, and fuel price are regulated by the government, gasoline price have been gradually increased since 2009. Price rise for RON97 is more significant. By 2014, its per liter price is 38% more than that of RON95. This has resulted in escalated dissatisfaction among the mass. People argued they were denied from using a better fuel (RON97). In order to evaluate the claim, there is a need to investigate engine response to these two gasoline grades. The effect of gasoline RON95 and RON97 on performance and exhaust emissions in spark ignition engine was investigated on a representative engine: 1.6L, 4-cylinder Mitsubishi 4G92 engine with CR 11:1. The engine was run at constant speed between 1500 and 3500 rpm with 500 rpm increment at various part-load conditions. The original engine ECU, a hydraulic dynamometer and control, a combustion analyzer and an exhaust gas analyzer were used to determine engine performance, cylinder pressure and emissions. Results showed that RON95 produced higher engine performance for all part-load conditions within the speed range. RON95 produced on average 4.4% higher brake torque, brake power, brake mean effective pressure as compared to RON97. The difference in engine performance was more significant at higher engine speed and loads. Cylinder pressure and ROHR were evaluated and correlated with engine output. With RON95, the engine produces 2.3% higher fuel conversion efficiency on average but RON97 was advantageous with 2.3% lower brake specific fuel consumption throughout all load condition. In terms of exhaust emissions, RON95 produced 7.7% lower \\{NOx\\} emission but higher CO2, CO and HC emissions by 7.9%, 36.9% and 20.3% respectively. Higher octane rating of gasoline may not necessarily beneficial on engine power, fuel economy and emissions of polluting gases. Even though there is some advantage using RON97 in terms of emission reduction of CO2, CO and HC, the 38% higher price and higher \\{NOx\\} emission is more expensive in the long run. Therefore using RON95 is economically better and environmentally friendlier. The findings provide some techno-economic evaluation on the fuel price debate that surround the Malaysia’s population in the recent years. The increased of fuel price may have limited their ability to use higher octane gasoline but it did not negatively affecting the users as they perceive.

Taib Iskandar Mohamad; Heoy Geok How

2014-01-01T23:59:59.000Z

138

Maximizing Power Output in Homogeneous Charge Compression Ignition (HCCI) Engines and Enabling Effective Control of Combustion Timing  

E-Print Network [OSTI]

In a locomotive application, Diesel-electric powertrains areaspect of electric motors. Although Diesel engines provide

Saxena, Samveg

2011-01-01T23:59:59.000Z

139

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering 2012 Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper

Jerby, Eli

140

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network [OSTI]

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper presents

Jerby, Eli

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Fuel Effects on Ignition and Their Impact on Advanced Combustion...  

Broader source: Energy.gov (indexed) [DOE]

Ignition and Their Impact on Advanced Combustion Engines Joshua D. Taylor - National Renewable Energy Laboratory Stuart Neill, Hailin Li - National Research Council Canada...

142

Advanced CFD Models for High Efficiency Compression Ignition...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion. p-19raja.pdf More Documents &...

143

Effect of the Addition of Diglyme in Diesel Fuel on Combustion and Emissions in a Compression?Ignition Engine  

Science Journals Connector (OSTI)

In the application of pure oxygenated fuels, Fleisch et al.,1 Kapus et al.,2 and Sorenson et al.3 have studied dimethyl ether (DME) in the modified diesel engine, and their results showed that the engine could achieve ultralow emission prospects without fundamental changes in combustion systems. ... 16 Mitsuo et al.17 investigated the effects of DGM on engine exhaust emissions in three different diesel engines. ... (18)?Heywood, J. B. Internal Combustion Engine Fundamentals; McGraw-Hill Book Company, New York, 1988. ...

Yi Ren; Zuohua Huang; Haiyan Miao; Deming Jiang; Ke Zeng; Bing Liu; Xibin Wang

2007-07-17T23:59:59.000Z

144

Investigation on characteristics of ionization current in a spark-ignition engine fueled with natural gas–hydrogen blends with BSS de-noising method  

Science Journals Connector (OSTI)

Investigation on ionization current characteristic in a spark-ignition engine fueled with natural gas, natural gas–hydrogen bends and gasoline was conducted. Blind Source Separation (BSS) de-noising method is employed to separate the ionization current signal from the interference of spark tail generated by ignition discharge. Cylinder pressure was recorded, and local temperature at spark plug gap is calculated using AVL-FIRE simulation code. Results show that the simulated cylinder pressures are in good agreement with those of measured and the spark tail and ionization current can be separated using BSS method. Front flame stage and post flame stage in ionization current can be used to analyze the combustion characteristics of natural gas–hydrogen blends. De-noised current shows that the appearance of front flame stage and post flame stage (including the peaks in the stages) fueled with natural gas is postponed and compared with that fueled with gasoline, and the appearance of front flame stage and post flame stage advance with the increase of hydrogen fraction in natural gas–hydrogen blends. In addition, the amplitude of ionization currents in both front flame and post flame (including the two peaks) fueled with natural gas gives lower values compared with those fueled with gasoline and hydrogen addition can increase the amplitude. Maximum post flame current shows similar trend to maximum cylinder pressure and it has good correlation between the timing of maximum post flame current and the timing of maximum cylinder pressure. High correlation coefficient between maximum post flame current and maximum pressure is presented.

Zhongquan Gao; Xiaomin Wu; Hui Gao; Bing Liu; Jie Wang; Xiangwen Meng; Zuohua Huang

2010-01-01T23:59:59.000Z

145

Combustion Characterization and Ignition Delay Modeling of Low- and High-Cetane Alternative Diesel Fuels in a Marine Diesel Engine  

Science Journals Connector (OSTI)

Mechanical and Aerospace Engineering Department, U.S. Naval Postgraduate School, Watkins Hall 700 Dyer Road Monterey, California 93943-5100, United States ... However, this study was done using an indirect injection diesel engine that may be uncharacteristic for typical diesel engines, which utilize direct injection. ... The IGD can, in turn, be used to provide qualitative or even quantitative prediction of other operational parameters such as peak pressure, maximum rate of pressure rise, or the general viability of the fuel in a diesel engine. ...

John Petersen; Doug Seivwright; Patrick Caton; Knox Millsaps

2014-07-10T23:59:59.000Z

146

Performance and Emissions of a Compression-Ignition Engine Fueled with Dimethyl Ether and Rapeseed Oil Blends  

Science Journals Connector (OSTI)

Sorenson and Mikkelsen2 had studied DME in a modified diesel engine, and their results showed that the engine could achieve ultralow-emission prospects without a fundamental change in combustion systems. ... Meanwhile, these parameters are compared with those of pure diesel fuel in order to clarify the effect of blends on the combustion and emission of engines (a CI engine cannot run for much longer of a period with pure DME fuel, so a comparison is only made with pure diesel fuel). ... Moreover, owing to the lower calorific value of the blend compared to diesel fuel, the fuel supply amount per cycle for blend operation is enlarged by increasing the plunger stroke of the fuel pump in order to make the power and torque output of the blends approach those of the corresponding diesel engine. ...

Wang Ying; Zhou Longbao

2007-04-20T23:59:59.000Z

147

Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems  

SciTech Connect (OSTI)

Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

Westbrook, C.K.

2000-07-07T23:59:59.000Z

148

Ignition problems in scramjet testing  

SciTech Connect (OSTI)

Ignition of H{sub 2} in heated air containing H{sub 2}O, radicals, and dust was investigated for scramjet testing. Using a reduced kinetic model for H{sub 2}{minus}O{sub 2} systems, the effects of H{sub 2}O and radicals in nozzles are discussed in relation to engine testing with vitiation heaters. Analysis using linearized rate-equations suggested that the addition of O atoms was 1.5 times more effective than the addition of H atoms for ignition. This result can be applied to the problem of premature ignition caused by residual radicals and to plasma-jet igniters. Thermal and chemical effects of dust, inevitable in storage air heaters, were studied next. The effects of heat capacity and size of dust were expressed in terms of an exponential integral function. It was found that the radical termination on the surface of dust produces an effect equivalent to heat loss. The inhibition of ignition by dust may result, if the mass fraction of dust becomes 10{sup {minus}3}.

Mitani, Tohru [National Aerospace Lab., Miyagi (Japan)] [National Aerospace Lab., Miyagi (Japan)

1995-05-01T23:59:59.000Z

149

Emissions and fuel economy of a vehicle with a spark-ignition, direct-injection engine : Mitsubishi Legnum GDI{trademark}.  

SciTech Connect (OSTI)

A 1997 Mitsubishi Legnum station wagon with a 150-hp, 1.8-L, spark-ignition, direct-injection (SIDI) engine was tested for emissions by using the FTP-75, HWFET, SC03, and US06 test cycles and four different fuels. The purpose of the tests was to obtain fuel-economy and emissions data on SIDI vehicles and to compare the measurements obtained with those of a port-fuel-injection (PFI) vehicle. The PFI vehicle chosen for the comparison was a 1995 Dodge Neon, which meets the Partnership for a New Generation of Vehicles (PNGV) emissions goals of nonmethane hydrocarbons (NMHC) less than 0.125 g/mi, carbon monoxide (CO) less than 1.7 g/mi, nitrogen oxides (NO{sub x} ) less than 0.2 g/mi, and particulate matter (PM) less than 0.01 g/mi. The Mitsubishi was manufactured for sale in Japan and was not certified to meet current US emissions regulations. Results show that the SIDI vehicle can provide up to 24% better fuel economy than the PFI vehicle does, with correspondingly lower greenhouse gas emissions. The SIDI vehicle as designed does not meet the PNGV goals for NMHC or NO{sub x} emissions, but it does meet the goal for CO emissions. Meeting the goal for PM emissions appears to be contingent upon using low-sulfur fuel and an oxidation catalyst. One reason for the difficulty in meeting the NMHC and NO{sub x} goals is the slow (200 s) warm-up of the catalyst. Catalyst warm-up time is primarily a matter of design. The SIDI engine produces more NMHC and NO{sub x} than the PFI engine does, which puts a greater burden on the catalyst to meet the emissions goals than is the case with the PFI engine. Oxidation of NMHC is aided by unconsumed oxygen in the exhaust when the SIDI engine operates in stratified-charge mode, but the same unconsumed oxygen inhibits chemical reduction of NO{sub x} . Thus, meeting the NO{sub x} emissions goal is likely to be the greatest challenge for the SIDI engine.

Cole, R. L.; Poola, R. B.; Sekar, R.

1999-04-08T23:59:59.000Z

150

Mathematical analysis of spark ignition engine operation via the combination of the first and second laws of thermodynamics  

Science Journals Connector (OSTI)

...exh exergy transfer with exhaust gases, J A f area of flame front, m2...diameter, m E energy, J f mass residual gas fraction, dimensionless h specific...engine. Trans. ASME J. Eng. Gas Turbines Power. 110, 462-469. Bayraktar...

2008-01-01T23:59:59.000Z

151

Thermonuclear Ignition of Dark Galaxies  

E-Print Network [OSTI]

thermonuclear ignition of stars by nuclear fission, and the corollary, non-ignition of stars. The possibility of

J. Marvin Herndon

2006-01-01T23:59:59.000Z

152

Laser preheat enhanced ignition  

DOE Patents [OSTI]

A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided.

Early, James W. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

153

Laser preheat enhanced ignition  

DOE Patents [OSTI]

A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided. 11 figs.

Early, J.W.

1999-03-02T23:59:59.000Z

154

Thermal ignition combustion system  

DOE Patents [OSTI]

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

155

Thermal ignition combustion system  

SciTech Connect (OSTI)

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

1988-01-01T23:59:59.000Z

156

Laser Spark Distribution and Ignition System  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Spark Distribution and Ignition System Spark Distribution and Ignition System Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implement- ing United States Patent Number 7,421,166 entitled "Laser Spark Distribution and Ignition System." Disclosed in this patent is NETL's laser spark distribution and ignition system, which reduces the high-power optical requirements normally needed for such a system by using optical fibers to deliver low-peak-energy pumping pulses to a laser amplifier or laser oscillator. Laser spark generators then produce a high-peak-power laser spark from a single low power pulse. The system has ap- plications in natural gas fueled reciprocating engines, turbine combustors, explosives, and laser induced breakdown spectroscopy diagnostic sensors.

157

Investigations on emission characteristics of the pongamia biodiesel–diesel blend fuelled twin cylinder compression ignition direct injection engine using exhaust gas recirculation methodology and dimethyl carbonate as additive  

Science Journals Connector (OSTI)

Experiments were carried out on a twin cylinder direct injection compression ignition engine using pongamia biodiesel–diesel blend as fuel with exhaust gas recirculation (EGR) and dimethyl carbonate (DMC) as additive. The experimental results showed that pongamia biodiesel–diesel blend fuelled engine with EGR and DMC can simultaneously reduce smoke and nitric oxide ( NO x ) emission. The NO x emission was reduced by about 17.68% for 10% of EGR introduction and about 13.55% increase in smoke emission. When dimethyl carbonate was added with EGR the engine emits lower smoke with lesser NO x emission and it showed that the smoke reduction rate had a linear relationship with DMC percentage. The carbon monoxide (CO) and hydrocarbon (HC) emissions also decreased when DMC was added. However the addition of DMC with EGR caused an increase in both BSEC and BTE.

M. Pandian; S. P. Sivapirakasam; M. Udayakumar

2010-01-01T23:59:59.000Z

158

Recent progress on the Compact Ignition Tokamak (CIT)  

SciTech Connect (OSTI)

This report describes work done on the Compact Ignition Tokamak (CIT), both at the Princeton Plasma Physics Laboratory (PPPL) and at other fusion laboratories in the United States. The goal of CIT is to reach ignition in a tokamak fusion device in the mid-1990's. Scientific and engineering features of the design are described, as well as projected cost and schedule.

Ignat, D.W.

1987-01-01T23:59:59.000Z

159

Effect of flow velocity and temperature on ignition characteristics in laser ignition of natural gas and air mixtures  

Science Journals Connector (OSTI)

Abstract Laser induced spark ignition offers the potential for greater reliability and consistency in ignition of lean air/fuel mixtures. This increased reliability is essential for the application of gas turbines as primary or secondary reserve energy sources in smart grid systems, enabling the integration of renewable energy sources whose output is prone to fluctuation over time. This work details a study into the effect of flow velocity and temperature on minimum ignition energies in laser-induced spark ignition in an atmospheric combustion test rig, representative of a sub 15 MW industrial gas turbine (Siemens Industrial Turbomachinery Ltd., Lincoln, UK). Determination of minimum ignition energies required for a range of temperatures and flow velocities is essential for establishing an operating window in which laser-induced spark ignition can operate under realistic, engine-like start conditions. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 532 nm wavelength and 4 ns pulse length. Analysis of the influence of flow velocity and temperature on ignition characteristics is presented in terms of required photon flux density, a useful parameter to consider during the development laser ignition systems.

J. Griffiths; M.J.W. Riley; A. Borman; C. Dowding; A. Kirk; R. Bickerton

2015-01-01T23:59:59.000Z

160

Plasma-assisted ignition and deflagration-to-detonation transition  

Science Journals Connector (OSTI)

...Forman A. Williams Plasma-assisted ignition...correspondence ( astariko@princeton.edu ). 1 Mechanical...Aerospace Engineering, Princeton University, , Princeton, NJ-08544, USA...Non-equilibrium plasma demonstrates great...

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Advanced aircraft ignition CRADA final report  

SciTech Connect (OSTI)

Conventional commercial and military turbo-jet aircraft engines use capacitive discharge ignition systems to initiate fuel combustion. The fuel-rich conditions required to ensure engine re-ignition during flight yield less than optimal engine performance, which in turn reduces fuel economy and generates considerable pollution in the exhaust. Los Alamos investigated two approaches to advanced ignition: laser based and microwave based. The laser based approach is fuel ignition via laser-spark breakdown and via photo-dissociation of fuel hydrocarbons and oxygen. The microwave approach involves modeling, and if necessary redesigning, a combustor shape to form a low-Q microwave cavity, which will ensure microwave breakdown of the air/fuel mixture just ahead of the nozzle with or without a catalyst coating. This approach will also conduct radio-frequency (RF) heating of ceramic elements that have large loss tangents. Replacing conventional systems with either of these two new systems should yield combustion in leaner jet fuel/air mixtures. As a result, the aircraft would operate with (1) considerable less exhaust pollution, (2) lower engine maintenance, and (3) significantly higher fuel economy.

Early, J.W.

1997-03-01T23:59:59.000Z

162

IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES  

SciTech Connect (OSTI)

This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

Jason M. Keith

2005-02-01T23:59:59.000Z

163

Laser-induced spark ignition fundamental and applications  

Science Journals Connector (OSTI)

Laser ignition has become an active research topic in recent years because it has the potential to replace the conventional electric spark plugs in engines that are required to operate under much higher compression ratios, faster compression rates, and much leaner fuel-to-air ratios than gas engines today. It is anticipated that the igniter in these engines will face with pressures as high as 50 MPa and temperatures as high as 4000 K. Using the conventional ignition system, the required voltage and energy must be greatly increased (voltages in excess of 40 kV) to reliably ignite the air and fuel mixture under these conditions. Increasing the voltage and energy does not always improve ignitability but it does create greater reliability problem. The objective of this paper is to review past work to identify some fundamental issues underlying the physics of the laser spark ignition process and research needs in order to bring the laser ignition concept into the realm of reality.

Tran X. Phuoc

2006-01-01T23:59:59.000Z

164

Laser ignition studies  

SciTech Connect (OSTI)

The goal of this work is to study the details of laser induced ignition and combustion of high-temperature condensed-phase exothermic reactions. In this work high-speed photography (HSP) and real-time optical pyrometry have been combined to provide a diagnostic tool with a 1 ms temporal resolution for studying laser ignition and combustion wave propagation. Previous experiments have involved the use of HSP for studying combustion wave propagation (1) Real-time pyrometry studies of the ignition process have also been performed previously. The present paper describes how HSP has been expanded to include three-view split-frame photography to allow the ignition and combustion processes to be recorded and studied simultaneously. 2 refs., 3 figs.

Fredin, L.; Hansen, G.P.; Margrave, J.L.; Behrens, R.G.

1985-10-01T23:59:59.000Z

165

Groundbreaking at National Ignition Facility | National Nuclear...  

National Nuclear Security Administration (NNSA)

Ignition Facility May 29, 1997 Groundbreaking at National Ignition Facility Livermore, CA Secretary Pena participates in the ground breaking ceremony for the National Ignition...

166

Gas-Fired Reciprocating Engines  

Broader source: Energy.gov [DOE]

The reciprocating, or piston-driven, engine is a widespread and well-known technology. Also called internal combustion engines, reciprocating engines require fuel, air, compression, and a combustion source to function. Depending on the ignition source, they generally fall into two categories: (1) spark-ignited engines, typically fueled by gasoline or natural gas, and (2) compression-ignited engines, typically fueled by diesel oil fuel.

167

National Ignition Facility & Photon Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

5 National Ignition Facility & Photon Science how do Lasers work? how Do Lasers work? A laser can be as small as a microscopic computer chip or as immense as the National Ignition...

168

Evaluation of Ethanol and Water Introduction via Fumigation on Efficiency and Emissions of a Compression Ignition Engine Using an Atomization Technique.  

E-Print Network [OSTI]

??Performance of a diesel engine, equipped for ethanol and water fumigation, was studied. The method implemented allowed for non-destructive introduction of liquids in advance of… (more)

Janousek, Grant S

2010-01-01T23:59:59.000Z

169

Multidimensional modeling of diesel ignition and combustion using a multistep kinetics model  

SciTech Connect (OSTI)

Ignition and combustion mechanisms in diesel engines were studied using the KIVA code, with modifications to the combustion, heat transfer, crevice flow, and spray models. A laminar-and-turbulent characteristic-time combustion model that has been used successfully for spark-ignited engine studies was extended to allow predictions of ignition and combustion in diesel engines. A more accurate prediction of ignition delay was achieved by using a multistep chemical kinetics model. The Shell knock model was implemented for this purpose and was found to be capable of predicting successfully the autoignition of homogeneous mixtures in a rapid compression machine and diesel spray ignition under engine conditions. The physical significance of the model parameters is discussed and the sensitivity of results to the model constants is assessed. The ignition kinetics model was also applied to simulate the ignition process in a Cummins diesel engine. The post-ignition combustion was simulated using both a single-step Arrhenius kinetics model and also the characteristic-time model to account for the energy release during the mixing-controlled combustion phase. The present model differs from that used in earlier multidimensional computations of diesel ignition in that it also includes state-of-the-art turbulence and spray atomization models. In addition, in this study the model predictions are compared to engine data. It is found that good levels of agreement with the experimental data are obtained using the multistep chemical kinetics model for diesel ignition modeling. However, further study is needed of the effects of turbulent mixing on post-ignition combustion.

Kong, S.C.; Reitz, R.D. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering)

1993-10-01T23:59:59.000Z

170

High compression ratio turbo gasoline engine operation using alcohol enhancement  

E-Print Network [OSTI]

Gasoline - ethanol blends were explored as a strategy to mitigate engine knock, a phenomena in spark ignition engine combustion when a portion of the end gas is compressed to the point of spontaneous auto-ignition. This ...

Lewis, Raymond (Raymond A.)

2013-01-01T23:59:59.000Z

171

An Experimental Investigation of the Origin of Increased NOx Emissions When Fueling a Heavy-Duty Compression-Ignition Engine with Soy Biodiesel  

Broader source: Energy.gov [DOE]

Optical engine experiments suggest that near stoichiometric charge-gas mixtures in the standing premixed autoignition zone near flame lift-off length explains biodiesel NOx increase under all conditions

172

Integrated Fast Ignition Simulation of Cone-guided Target with Three Codes  

E-Print Network [OSTI]

. #12;Then an ultrahigh intense ignition laser is launched into the plasma, and we can simulate laserIntegrated Fast Ignition Simulation of Cone-guided Target with Three Codes H. Sakagami1) , T, Himeji, Hyogo 671-2201 Japan 2) Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita

Paris-Sud XI, Université de

173

Burner ignition system  

DOE Patents [OSTI]

An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

Carignan, Forest J. (Bedford, MA)

1986-01-21T23:59:59.000Z

174

COLLOQUIUM: In Pursuit of Ignition on the National Ignition Facility...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the Lawrence Livermore National Laboratory with the goal of igniting a propagating thermonuclear burn wave in DT fuel leading to energy gain (defined as fusion yieldinput laser...

175

Central ignition scenarios for TFTR  

SciTech Connect (OSTI)

The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs.

Zweben, S.J.; Redi, M.H.; Bateman, G.

1986-03-01T23:59:59.000Z

176

Ignition enhancement for scramjet combustion.  

E-Print Network [OSTI]

??The process of shock-induced ignition has been investigated both computa- tionally and experimentally, with particular emphasis on the concept of radical farming. The first component… (more)

McGuire, Jeffrey Robert

2007-01-01T23:59:59.000Z

177

Multidimensional CFD simulation of syngas combustion in a micro-pilot-ignited dual-fuel engine using a constructed chemical kinetics mechanism  

Science Journals Connector (OSTI)

A multidimensional computational fluid dynamics (CFD) simulation of a constructed syngas chemical kinetic mechanism was performed to evaluate the combustion of syngas in a supercharged dual-fuel engine for various syngas initial compositions under lean conditions. The modelled results were validated by comparing predictions against corresponding experimental data for a supercharged dual-fuel engine. The predicted and measured in-cylinder pressure, temperature, and rate of heat release (ROHR) data were in good agreement. The effect of the hydrogen peroxide chain-propagation reaction on the progress of combustion under supercharged conditions was examined for different types of syngas using various initial H2 concentrations. The effect of the main syngas kinetic mechanism reactions on the combustion progress was analysed in terms of their contribution to the total heat of the reaction. The best results compared with experimental data were obtained in the range of equivalence ratios below about 0.8 for all types of syngas considered in this paper. As the equivalence ratio increased above 0.8, the results deviated from the experiment data. The spatial distribution of the in-cylinder temperature and OH? within this equivalence-ratio range showed the completeness of the combustion. The present CFD model captured the overall combustion process well and could be further developed into a useful tool for syngas-engine combustion simulations.

Ulugbek Azimov; Masahiro Okuno; Kazuya Tsuboi; Nobuyuki Kawahara; Eiji Tomita

2011-01-01T23:59:59.000Z

178

Laser Ignition of Single Magnesium Particles  

Science Journals Connector (OSTI)

The minimum ignition temperature and minimum ignition energy of single magnesium particles was determined ... levitated ultrasonically and was ignited by a short laser pulse. The temperature transient of the part...

J. F. Zevenbergen; A. E. Dahoe…

2000-01-01T23:59:59.000Z

179

Predicting Ignition Delay for Gas Turbine Fuel Flexibility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ignition Delay for Ignition Delay for Gas Turbine Fuel Flexibility 15 ÎĽm * Low emission combustion systems have been carefully optimized for natural gas * Future fuel diversity (including H2 containing fuels) may generate auto-ignition damage * Existing theories vary in predicting propensity for auto-ignition damage * Theory A vs Theory B shows factor of 100 difference-which is right? * UC Irvine improved and validated design tools for ignition delay allow designers to evaluate the risk for auto-ignition in advanced combustion systems with future fuels * Models are available to engine OEM's to shorten design cycle time and save $$ UC Irvine Scott Samuelsen / Vince McDonell #112 1000/T (1/K) 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 Ď„ [O 2 ] 0.5 [F] 0.25 (sec(mol/cm 3 ) 0.75 ) 10 -10 10 -9 10 -8 10 -7 10 -6 10 -5

180

Laser spark distribution and ignition system  

DOE Patents [OSTI]

A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

Woodruff, Steven (Morgantown, WV); McIntyre, Dustin L. (Morgantown, WV)

2008-09-02T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Premix charge, compression ignition combustion system optimization...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Premix charge, compression ignition combustion system optimization Premix charge, compression ignition combustion system optimization Presentation given at DEER 2006, August 20-24,...

182

Princeton Plasma Physics Lab - National Ignition Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

national-ignition-facility National Ignition Facility en Summary of Assessment of Prospects for Inertial Fusion Energy http:www.pppl.govnode1361

183

Ignition reactor and pump pulse parameters in a reactor–laser system  

Science Journals Connector (OSTI)

The experience gained in operating a demonstration nuclear-pumped laser in stand B (Physics and Power- Engineering Institute (FEI)) with a pulsed ignition reactor based on the 235U BARS-6 reactor is analyzed. It ...

P. P. D’yachenko; G. N. Fokin

2012-09-01T23:59:59.000Z

184

Impact of cetane improvers on ignition delay times of several alternative biofuels  

SciTech Connect (OSTI)

Biofuel technology could be approaching one of its greatest development milestones--being accepted as a standard item on new vehicle technology. In particular, the Partnership for a New Generation Vehicle (PNGV) lists the evaluation and possible utilization of alternative fuels as one of the technological focuses to be evaluated by the year 2000. Synergy 2010, Ford`s newest Taurus model concept car, includes the use of a 20:1 compression-ratio, compression-ignition (CI) engine as the preferred engine. The preferred fuels include diesel, gasoline, and methanol. Cetane improvers make methanol fuel practical with a 20:1 compression ratio engine such as that proposed with Synergy 2010 and are a key technology for biofuel success. CI engines have a high probability of becoming the preferred engines for PNGV vehicles since CI engines are 20% to 30% more efficient than spark-ignition engines. In addition, CI engines allow a wider range of viable biofuels to be used. This paper is on the impact of cetane improvers on methanol and other biofuels. Fuels are evaluated through ignition delay time studies in a constant volume combustor. Ignition delay times measured at several temperatures and with biofuels of different compositions provide much more data than conventional cetane numbers and provide an understanding which is essential to engineer biofuels for the best possible performance in new engines. Ignition delay times are reported for several biofuels including mixtures containing biodiesel, methanol, and syrup.

Suppes, G.J. [Univ. of Kansas, Lawrence, KS (United States); Bryan, M.; Chen, Z. [and others

1996-12-31T23:59:59.000Z

185

Fast Ignition Program Presented at  

E-Print Network [OSTI]

Laser drive Direct Laser drive #12;Fast Ignition may allow longer wavelength laser implosion systemsFast Ignition Program Presented at FESAC Development Path Panel General Atomics January 14, 2003 E. Michael Campbell ·Promise ·Status ·Challenges ·Implementation ·Plan #12;The original FI concept uses laser

186

Enabling and Expanding HCCI in PFI Gasoline Engines with High...  

Broader source: Energy.gov (indexed) [DOE]

of High Efficiency Engines Vehicle Technologies Office Merit Review 2014: Accelerating Predictive Simulation of IC Engines with High Performance Computing Ignition Control for HCCI...

187

Ignition distributor voltage generator  

SciTech Connect (OSTI)

This patent describes a voltage pulse generator and ignition distributor comprising, a base, a shaft rotatably supported by the base, a distributor cap supported by the base having a center electrode and circumferentially spaced outer electrodes. The pulse generator and ignition distribution also include a first rotor driven by the shaft formed of electrical insulating material having electrically conductive means connected to the center terminal and a portion that rotates past the outer electrodes. The portion of the electrically conductive means that rotates past the outer electrodes is spaced from the outer electrodes to form a gap therebetween. A voltage pulse generator comprises a second rotor driven by the shaft, at least one permanent magnet and an annular pickup coil supported by the base. The pickup coil has inner turns and outer turns, the beginning turn of the inner turns connected to a first lead and the last turn of the outer turns connected to a second lead, the outer turns enclosing the inner turns. The pickup coil also has a circuit connected directly between the second lead and ground which is operative to provide a direct conductive path to ground for high frequency energy capacitively coupled to the outer turns from the gap discharge between the electrically conductive means of the first rotor and an outer electrode, the outer turns forming a grounded shield for the inner turns.

Boyer, J.A.

1986-11-04T23:59:59.000Z

188

Plastic ablator ignition capsule design for the National Ignition Facility  

SciTech Connect (OSTI)

This paper describes current efforts to develop a plastic ablator capsule design for the first ignition attempt on the National Ignition Facility. The trade-offs in capsule scale and laser energy that must be made to achieve ignition probabilities comparable to those with other candidate ablators, beryllium and high-density carbon, are emphasized. Large numbers of 1-D simulations, meant to assess the statistical behavior of the target design, as well as 2-D simulations to assess the target's susceptibility to Rayleigh-Taylor growth are discussed.

Clark, D S; Haan, S W; Hammel, B A; Salmonson, J D; Callahan, D A; Town, R J

2009-10-06T23:59:59.000Z

189

Direct Injection Compression Ignition Diesel Automotive Technology Education GATE Program  

SciTech Connect (OSTI)

The underlying goal of this prqject was to provide multi-disciplinary engineering training for graduate students in the area of internal combustion engines, specifically in direct injection compression ignition engines. The program was designed to educate highly qualified engineers and scientists that will seek to overcome teclmological barriers preventing the development and production of cost-effective high-efficiency vehicles for the U.S. market. Fu1iher, these highly qualified engineers and scientists will foster an educational process to train a future workforce of automotive engineering professionals who are knowledgeable about and have experience in developing and commercializing critical advanced automotive teclmologies. Eight objectives were defmed to accomplish this goal: 1. Develop an interdisciplinary internal co1nbustion engine curriculum emphasizing direct injected combustion ignited diesel engines. 2. Encourage and promote interdisciplinary interaction of the faculty. 3. Offer a Ph.D. degree in internal combustion engines based upon an interdisciplinary cuniculum. 4. Promote strong interaction with indusuy, develop a sense of responsibility with industry and pursue a self sustaining program. 5. Establish collaborative arrangements and network universities active in internal combustion engine study. 6. Further Enhance a First Class educational facility. 7. Establish 'off-campus' M.S. and Ph.D. engine programs of study at various indusuial sites. 8. Extend and Enhance the Graduate Experience.

Carl L. Anderson

2006-09-25T23:59:59.000Z

190

Conceptual Design - Polar Drive Ignition Campaign  

SciTech Connect (OSTI)

The Laboratory for Laser Energetics (LLE) at the University of Rochester is proposing a collaborative effort with Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratories (LANL), the Naval Research Laboratory (NRL), and General Atomics (GA) with the goal of developing a cryogenic polar drive (PD) ignition platform on the National Ignition Facility (NIF). The scope of this proposed project requires close discourse among theorists, experimentalists, and laser and system engineers. This document describes how this proposed project can be broken into a series of parallel independent activities that, if implemented, could deliver this goal in the 2017 timeframe. This Conceptual Design document is arranged into two sections: mission need and design requirements. Design requirements are divided into four subsystems: (1) A point design that details the necessary target specifications and laser pulse requirements; (2) The beam smoothing subsystem that describes the MultiFM 1D smoothing by spectral dispersion (SSD); (3) New optical elements that include continuous phase plates (CPP's) and distributed polarization rotators (DPR's); and (4) The cryogenic target handling and insertion subsystem, which includes the design, fabrication, testing, and deployment of a dedicated PD ignition target insertion cryostat (PD-ITIC). This document includes appendices covering: the primary criteria and functional requirements, the system design requirements, the work breakdown structure, the target point design, the experimental implementation plan, the theoretical unknowns and technical implementation risks, the estimated cost and schedule, the development plan for the DPR's, the development plan for MultiFM 1D SSD, and a list of acronym definitions. While work on the facility modifications required for PD ignition has been in progress for some time, some of the technical details required to define the specific modifications for a Conceptual Design Review (CDR) remain to be defined. In all cases, the facility modifications represent functional changes to existing systems or capabilities. The bulk of the scope yet to be identified is associated with the DPR's and MultiFM beam smoothing. Detailed development plans for these two subsystems are provided in Appendices H and I; additional discussion of subsystem requirements based on the physics of PD ignition is given in Section 3. Accordingly, LLE will work closely with LLNL to develop detailed conceptual designs for the PD-specific facility modifications, including assessments of the operational impact of implementation (e.g., changing optics for direct rather than indirect-drive illumination and swapping from a hohlraum-based ITIC to one that supports PD). Furthermore, the experimental implementation plan represents the current best understanding of the experimental campaigns required to achieve PD ignition. This plan will evolve based on the lessons learned from the National Ignition Campaign (NIC) and ongoing indirect-drive ignition experiments. The plan does not take the operational realities of the PD configuration into account; configuration planning for the proposed PD experiments is beyond the scope of this document.

Hansen, R

2012-04-05T23:59:59.000Z

191

Advanced ignition options for laser ICF  

E-Print Network [OSTI]

Advanced ignition options for laser ICF FPA Meeting, Washington DC, December 1-3, 2010 R. Betti shock) · Fast Ignition requires major hardware upgrades: 100kJ-class multi-PW laser [also talk by P explore high-gain shock ignition - Polar Shock Ignition (uses half the NIF beams to drive the implosion

192

The National Ignition Facility and the Ignition Campaign  

E-Print Network [OSTI]

February 14-18, 2013 Debra A. Callahan Group Leader for ICF/IFE Target design Lawrence Livermore National(atm-s) Indirect drive on the NIF is within a factor of 2-3 of the conditions required for ignition Callahan -- AAAS, February 14-18, 2013 82013-047661s2.ppt NIF Ignition #12;2013-047661s2.ppt Callahan -- AAAS

193

Final Scientific and Technical Report - Practical Fiber Delivered Laser Ignition Systems for Vehicles  

SciTech Connect (OSTI)

Research has characterized advanced kagome fiber optics for their use in laser ignition systems. In comparison to past fibers used in laser ignition, these fibers have the important advantage of being relatively bend-insensitivity, so that they can be bent and coiled without degradation of output energy or beam quality. The results are very promising for practical systems. For pulse durations of ~12 ns, the fibers could deliver >~10 mJ pulses before damage onset. A study of pulse duration showed that by using longer pulse duration (~20 – 30 ns), it is possible to carry even higher pulse energy (by factor of ~2-3) which also provides future opportunities to implement longer duration sources. Beam quality measurements showed nearly single-mode output from the kagome fibers (i.e. M2 close to 1) which is the optimum possible value and, combined with their high pulse energy, shows the suitability of the fibers for laser ignition. Research has also demonstrated laser ignition of an engine including reliable (100%) ignition of a single-cylinder gasoline engine using the laser ignition system with bent and coiled kagome fiber. The COV of IMEP was <2% which is favorable for stable engine operation. These research results, along with the continued reduction in cost of laser sources, support our commercial development of practical laser ignition systems.

Yalin, Azer [Seaforth, LLC

2014-03-30T23:59:59.000Z

194

TOWARD A STANDARD IGNITION SOURCE  

E-Print Network [OSTI]

and ignited with a small propane torch. The top center ofhead is supplied with propane. In these experiments allin the pre-mixed mode with propane alone to simulate trash

Volkingburg, David R. Van

2011-01-01T23:59:59.000Z

195

National Ignition Facility (NIF): Under Pressure: Ramp-Compression...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

National Ignition Facility (NIF): Under Pressure: Ramp-Compression Smashes Record American Fusion News Category: National Ignition Facility Link: National Ignition Facility (NIF):...

196

National Ignition Campaign Hohlraum Energetics  

SciTech Connect (OSTI)

The first series of experiments on the National Ignition Facility (NIF) [E. I. Moses, R. N. Boyd, B. A. Remington, C. J. Keane, and R. Al-Ayat, 'The National Ignition Facility: ushering in a new age for high energy density science,' Phys. Plasmas 16, 041006 (2009)] tested ignition hohlraum 'energetics,' a term described by four broad goals: (1) Measurement of laser absorption by the hohlraum; (2) Measurement of the x-ray radiation flux (T{sub RAD}{sup 4}) on the surrogate ignition capsule; (3) Quantitative understanding of the laser absorption and resultant x-ray flux; and (4) Determining whether initial hohlraum performance is consistent with requirements for ignition. This paper summarizes the status of NIF hohlraum energetics experiments. The hohlraum targets and experimental design are described, as well as the results of the initial experiments. The data demonstrate low backscattered energy (< 10%) for hohlraums filled with helium gas. A discussion of our current understanding of NIF hohlraum x-ray drive follows, including an overview of the computational tools, i.e., radiation-hydrodynamics codes, that have been used to design the hohlraums. The performance of the codes is compared to x-ray drive and capsule implosion data from the first NIF experiments. These results bode well for future NIF ignition hohlraum experiments.

Meezan, N B; Atherton, L J; Callahan, D A; Dewald, E L; Dixit, S N; Dzenitis, E G; Edwards, M J; Haynam, C A; Hinkel, D E; Jones, O S; Landen, O; London, R A; Michel, P A; Moody, J D; Milovich, J L; Schneider, M B; Thomas, C A; Town, R J; Warrick, A L; Weber, S V; Widmann, K; Glenzer, S H; Suter, L J; MacGowan, B J; Kline, J L; Kyrala, G A; Nikroo, A

2009-11-16T23:59:59.000Z

197

Sandia National Laboratories: Optimizing Engines for Alternative...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Combustion Lab (TCL) Captures the Moment of Hydrogen Ignition Optimizing Engines for Alternative Fuels On September 10, 2013, in CRF, Energy, Facilities, News, News & Events,...

198

Modeling of High Efficiency Clean Combustion Engines  

Broader source: Energy.gov (indexed) [DOE]

2005, Accepted for Publication, Journal of Energy Resources Technology. 9. Effect of Laser-induced Excitation of Oxygen on Ignition in HCCI Engines Analyzed by Numerical...

199

National Ignition Facility project acquisition plan  

SciTech Connect (OSTI)

The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility (NIF) Project. The scope of the plan describes the procurement activities and acquisition strategy for the following phases of the NIF Project, each of which receives either plant and capital equipment (PACE) or other project cost (OPC) funds: Title 1 and 2 design and Title 3 engineering (PACE); Optics manufacturing facilitization and pilot production (OPC); Convention facility construction (PACE); Procurement, installation, and acceptance testing of equipment (PACE); and Start-up (OPC). Activities that are part of the base Inertial Confinement Fusion (ICF) Program are not included in this plan. The University of California (UC), operating Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory, and Lockheed-Martin, which operates Sandia National Laboratory (SNL) and the University of Rochester Laboratory for Laser Energetics (UR-LLE), will conduct the acquisition of needed products and services in support of their assigned responsibilities within the NIF Project structure in accordance with their prime contracts with the Department of Energy (DOE). LLNL, designated as the lead Laboratory, will have responsibility for all procurements required for construction, installation, activation, and startup of the NIF.

Callaghan, R.W.

1996-04-01T23:59:59.000Z

200

Enhanced Model for Fast Ignition  

SciTech Connect (OSTI)

Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nationâ??s energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, â??implicitness and fluid modeling,â?ť can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

Dr. Rodney J. Mason

2010-10-12T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Shockwave Engine: Wave Disk Engine  

SciTech Connect (OSTI)

Broad Funding Opportunity Announcement Project: MSU is developing a new engine for use in hybrid automobiles that could significantly reduce fuel waste and improve engine efficiency. In a traditional internal combustion engine, air and fuel are ignited, creating high-temperature and high-pressure gases which expand rapidly. This expansion of gases forces the engine’s pistons to pump and powers the car. MSU’s engine has no pistons. It uses the combustion of air and fuel to build up pressure within the engine, generating a shockwave that blasts hot gas exhaust into the blades of the engine’s rotors causing them to turn, which generates electricity. MSU’s redesigned engine would be the size of a cooking pot and contain fewer moving parts—reducing the weight of the engine by 30%. It would also enable a vehicle that could use 60% of its fuel for propulsion.

None

2010-01-14T23:59:59.000Z

202

Group pyrolysis, ignition, and combustion of a spherical cloud of coal particles  

E-Print Network [OSTI]

GROUP PYROLYSIS, IGNITION, AND COMBUSTION OF A SPHERICAL CLOUD OF COAL PARTICLES A Thesis by WILLIAM RICHARD RYAN, JR. Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree MASTER OF SCIENCE December 1988 Major Subject: Mechanical Engineering GROUP PYROLYSIS, IGNITION, AND COMBUSTION OF A SPHERICAL CLOUD OF COAL PARTICLES A Thesis by WIL LI AM RI C HA RD RYA N ~ JR Approved ss to style and content by...

Ryan, William Richard

1988-01-01T23:59:59.000Z

203

Laser Ignition of Alternative Liquid Fuels  

Science Journals Connector (OSTI)

Within a research project at the TU Vienna, the potential and mechanism of laser-induced ignition with respect to mixture inflammation and combustion were investigated compared to conventional spark ignition. A s...

Dr. Josef Graf; Dr. Thomas Lauer; Univ.-Prof. Dr. Bernhard Geringer

2012-05-01T23:59:59.000Z

204

National Ignition Facility & Photon Science What  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

What is NiF? the national ignition Facility: bringing star Power to earth The National Ignition Facility (NIF) is the world's largest and highest energy laser system. NIF is an...

205

Thermonuclear Ignition of Dark Galaxies  

E-Print Network [OSTI]

Dark matter is thought to be at least an order of magnitude more abundant than luminous matter in the Universe, but there has yet to be an unambiguous identification of a wholly dark, galactic-scale structure. There is, however, increasing evidence that VIRGOHI 21 may be a dark galaxy. If VIRGOHI 21 turns out to be composed of dark stars, having approximately the same mass of stars found in luminous galaxies, it will pose an enigma within the framework of current astrophysical models, but will provide strong support for my concept, published in 1994 in the Proceedings of the Royal Society of London, of the thermonuclear ignition of stars by nuclear fission, and the corollary, non-ignition of stars. The possibility of galactic thermonuclear ignition is discussed from that framework and leads to my suggestion that the distribution of luminous stars in a galaxy may simply be a reflection of the galactic distribution of the heavy elements.

J. Marvin Herndon

2006-04-13T23:59:59.000Z

206

June 11, 1999: National Ignition Facility  

Broader source: Energy.gov [DOE]

June 11, 1999Secretary Richardson dedicates the National Ignition Facility target chamber at DOE's Lawrence Livermore National Laboratory.

207

Heating National Ignition Facility, Realistic Financial Planning...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

DOEEIS-0236, Oakland Operations Office, National Ignition Facility Final Supplemental Environmental Impact Statement to the Stockpile Stewardship and Management Programmatic...

208

Laser ablation based fuel ignition  

DOE Patents [OSTI]

There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

1998-01-01T23:59:59.000Z

209

Laser ablation based fuel ignition  

DOE Patents [OSTI]

There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

Early, J.W.; Lester, C.S.

1998-06-23T23:59:59.000Z

210

Instrumentation and controls of an ignited tokamak  

SciTech Connect (OSTI)

The instrumentation and controls (I and C) of an ignited plasma magnetically confined in a tokamak configuration needs increased emphasis in the following areas: (1) physics implications for control; (2) plasma shaping/position control; and (3) control to prevent disruptive instabilities. This document reports on the FY 1979 efforts in these and other areas. Also presented are discusssions in the areas of: (1) diagnostics suitable for the Engineering Test Facility (ETF); and (2) future research and development (R and D) needs. The appendices focus attention on some preliminary ideas about the measurement of the deuteron-triton (D-T) ratio in the plasma, synchrotron radiation, and divertor control. Finally, an appendix documenting the thermal consequences to the first wall of a MPD is presented.

Becraft, W.R.; Golzy, J.; Houlberg, W.A.; Kukielka, C.A.; Onega R.J.; Raju, G.V.S.; Stone, R.S.

1980-10-01T23:59:59.000Z

211

Confinement of ignition and yield on the National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented.

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

1996-06-14T23:59:59.000Z

212

Modeling of homogeneous charge compression ignition (HCCI) of methane  

SciTech Connect (OSTI)

The operation of piston engines on a compression ignition cycle using a lean, homogeneous charge has many potential attractive features. These include the potential for extremely low NO{sub x} and particulate emissions while maintaining high thermal efficiency and not requiring the expensive high pressure injection system of the typical modem diesel engine. Using the HCT chemical kinetics code to simulate autoignition of methane-air mixtures, we have explored the ignition timing, burn duration, NO{sub x} production, indicated efficiency and power output of an engine with a compression ratio of 15:1 at 1200 and 2400 rpm. HCT was modified to include the effects of heat transfer. This study used a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by varying the intake equivalence ratio and varying the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both heat and combustion product species. It is accomplished by varying the timing of the exhaust valve closure. Inlet manifold temperature was held constant at 330 Kelvins. Results show that there is a narrow range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NO{sub x} levels below 100 ppm.

Smith, J.R.; Aceves, S.M.; Westbrook, C.; Pitz, W.

1997-05-01T23:59:59.000Z

213

Effect of focal size on the laser ignition of compressed natural gas–air mixture  

Science Journals Connector (OSTI)

Abstract Laser ignition of compressed natural gas–air mixtures was investigated in a constant volume combustion chamber (CVCC) as well as in a single cylinder engine. Laser ignition has several potential advantages over conventional spark ignition system. Laser ignition relies on the fact that optical breakdown (plasma generation) in gases occurs at high intensities of ?1011 W/cm2. Such high intensities can be achieved by focusing a pulsed laser beam to small focal sizes. The focal spot size depends on several parameters such as laser wavelength, beam diameter at the converging lens, beam quality and focal length. In this investigation, the focal length of the converging lens and the beam quality were varied and the corresponding effects on minimum ignition energy as well as pressure rise were recorded. The flame kernel was visualized and correlated with the rate of pressure rise inside the combustion chamber. This investigation will be helpful in the optimization of laser and optics parameters in laser ignition. It was found that beam quality factor and focal length of focusing lens have a strong impact on the minimum ignition energy required for combustion. Combustion duration depends on the energy density at the focal spot and size of the flame kernel.

Dhananjay Kumar Srivastava; Ernst Wintner; Avinash Kumar Agarwal

2014-01-01T23:59:59.000Z

214

A polar-drive shock-ignition design for the National Ignition Facility  

SciTech Connect (OSTI)

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2013-05-15T23:59:59.000Z

215

Laser-assisted homogeneous charge ignition in a constant volume combustion chamber  

Science Journals Connector (OSTI)

Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 ?m. These water molecules absorb the incident erbium laser radiations (?=2.79 ?m) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to “auto-ignite” could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.

Dhananjay Kumar Srivastava; Martin Weinrotter; Henrich Kofler; Avinash Kumar Agarwal; Ernst Wintner

2009-01-01T23:59:59.000Z

216

Single-cylinder engine as a tool for developing new combustion processes  

Science Journals Connector (OSTI)

In the race to perfect the combustion process of tomorrow engine developers are focusing on ... ignition and diesel systems with stratified spark-ignition combustion processes along with a variety of technologies...

Frank Menzel; Thomas Seidel; Wulf Schmidt; Julius Pape; Lutz Stiegler

2006-03-01T23:59:59.000Z

217

Ignition quality determination of diesel fuels from hydrogen type distribution of hydrocarbons  

SciTech Connect (OSTI)

Hydrogen types of diesel like hydrocarbon fuels which have dominant effect on the ignition quality have been identified. A scheme of characterizing the chemistry of hydrocarbon fuels in terms of these hydrogen types using proton nuclear resonance spectrometry has been proposed. Using this analysis technique on 70 different diesel fuels, whose cetane numbers were determined on a number of standard cetane rating engines, an empirical expression which relates the ignition quality to the hydrogen type distribution of the fuels has been developed. The developed expression and the relationship between the ignition delay and cetane number imply that the effective activation energy term in the usual semiempirical ignition delay expression is not a constant for a given fuel but is a function of pressure and temperature as well as the fuel chemistry.

Gulder, O.L.; Glavincevski, B.

1986-02-01T23:59:59.000Z

218

Progress Toward Ignition on the National Ignition Facility  

SciTech Connect (OSTI)

The principal approach to ignition on the National Ignition Facility (NIF) is indirect drive. A schematic of an ignition target is shown in Figure 1. The laser beams are focused through laser entrance holes at each end of a high-Z cylindrical case, or hohlraum. The lasers irradiate the hohlraum walls producing x-rays that ablate and compress the fuel capsule in the center of the hohlraum. The hohlraum is made of Au, U, or other high-Z material. For ignition targets, the hohlraum is {approx}0.5 cm diameter by {approx}1 cm in length. The hohlraum absorbs the incident laser energy producing x-rays for symmetrically imploding the capsule. The fuel capsule is a {approx}2-mm-diameter spherical shell of CH, Be, or C filled with DT fuel. The DT fuel is in the form of a cryogenic layer on the inside of the capsule. X-rays ablate the outside of the capsule, producing a spherical implosion. The imploding shell stagnates in the center, igniting the DT fuel. NIC has overseen installation of all of the hardware for performing ignition experiments, including commissioning of approximately 50 diagnostic systems in NIF. The diagnostics measure scattered optical light, x-rays from the hohlraum over the energy range from 100 eV to 500 keV, and x-rays, neutrons, and charged particles from the implosion. An example of a diagnostic is the Magnetic Recoil Spectrometer (MRS) built by a collaboration of scientists from MIT, UR-LLE, and LLNL shown in Figure 2. MRS measures the neutron spectrum from the implosion, providing information on the neutron yield and areal density that are metrics of the quality of the implosion. Experiments on NIF extend ICF research to unexplored regimes in target physics. NIF can produce more than 50 times the laser energy and more than 20 times the power of any previous ICF facility. Ignition scale hohlraum targets are three to four times larger than targets used at smaller facilities, and the ignition drive pulses are two to five times longer. The larger targets and longer pulse lengths produce unique plasma conditions for laser-plasma instabilities that could reduce hohlraum coupling efficiency. Initial experiments have demonstrated efficient coupling of laser energy to x-rays. X-ray drive greater than 300 eV has been measured in gas-filled ignition hohlraum and shows the expected scaling with laser energy and hohlraum scale size. Experiments are now optimizing capsule implosions for ignition. Ignition conditions require assembling the fuel with sufficient density and temperature for thermonuclear burn. X-rays ablate the outside of the capsule, accelerating and spherically compressing the capsule for assembling the fuel. The implosion stagnates, heating the central core and producing a hot spot that ignites and burns the surrounding fuel. The four main characteristics of the implosion are shell velocity, central hot spot shape, fuel adiabat, and mix. Experiments studying these four characteristics of implosions are used to optimize the implosion. Integrated experiments using cryogenic fuel layer experiments demonstrate the quality of the implosion as the optimization experiments progress. The final compressed fuel conditions are diagnosed by measuring the x-ray emission from the hot core and the neutrons and charged particles produced in the fusion reactions. Metrics of the quality of the implosion are the neutron yield and the shell areal density, as well as the size and shape of the core. The yield depends on the amount of fuel in the hot core and its temperature and is a gauge of the energy coupling to the fuel. The areal density, the density of the fuel times its thickness, diagnoses the fuel assembly, which is measured using the fraction of neutrons that are down scattered passing through the dense shell. The yield and fraction of down scattered neutrons, or shell rho-r, from the cryogenic layered implosions are shown in Figure 3. The different sets of data represent results after a series of implosion optimization experiments. Both yield and areal density show significant increases as a result of the optimiza

Kauffman, R L

2011-10-17T23:59:59.000Z

219

REQUEST BY CUMMINS ENGINE COMPANY, INC., FOR AN ADVANCE WAIVER...  

Broader source: Energy.gov (indexed) [DOE]

of technologies to improve spark ignition natural gas engine efficiencies for automotive markets. Two other companies, Mack Truck and Deere & Company, are also subcontractors...

220

Diagnostics for Fast Ignition Science  

SciTech Connect (OSTI)

The concept for Electron Fast Ignition Inertial Confinement Fusion demands sufficient laser energy be transferred from the ignitor pulse to the assembled fuel core via {approx}MeV electrons. We have assembled a suite of diagnostics to characterize such transfer. Recent experiments have simultaneously fielded absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256eV; spherically bent crystal imagers at 4 and 8keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung and electron and proton spectrometers (along the same line of sight); nuclear activation samples and a picosecond optical probe based interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following laser-plasma interactions at extremely high intensities in both planar and conical targets. Augmented with accurate on-shot laser focal spot and pre-pulse characterization, these measurements are yielding new insight into energy coupling and are providing critical data for validating numerical PIC and hybrid PIC simulation codes in an area that is crucial for many applications, particularly fast ignition. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultra high intensity laser plasma interactions are discussed, together with implications for full-scale fast ignition experiments.

MacPhee, A; Akli, K; Beg, F; Chen, C; Chen, H; Clarke, R; Hey, D; Freeman, R; Kemp, A; Key, M; King, J; LePape, S; Link, A; Ma, T; Nakamura, N; Offermann, D; Ovchinnikov, V; Patel, P; Phillips, T; Stephens, R; Town, R; Wei, M; VanWoerkom, L; Mackinnon, A

2008-05-06T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Fast ignition of inertial confinement fusion targets  

SciTech Connect (OSTI)

Results of studies on fast ignition of inertial confinement fusion (ICF) targets are reviewed. The aspects of the fast ignition concept, which consists in the separation of the processes of target ignition and compression due to the synchronized action of different energy drivers, are considered. Criteria for the compression ratio and heating rate of a fast ignition target, the energy balance, and the thermonuclear gain are discussed. The results of experimental and theoretical studies of the heating of a compressed target by various types of igniting drivers, namely, beams of fast electrons and light ions produced under the action of a petawatt laser pulse on the target, a heavy-ion beam generated in the accelerator, an X-ray pulse, and a hydrodynamic flow of laser-accelerated matter, are analyzed. Requirements to the igniting-driver parameters that depend on the fast ignition criteria under the conditions of specific target heating mechanisms, as well as possibilities of practical implementation of these requirements, are discussed. The experimental programs of various laboratories and the prospects of practical implementation of fast ignition of ICF targets are reviewed. To date, fast ignition is the most promising method for decreasing the ignition energy and increasing the thermonuclear gain of an ICF plasma. A large number of publications have been devoted to investigations of this method and adjacent problems of the physics of igniting drivers and their interaction with plasma. This review presents results of only some of these studies that, in the author's opinion, allow one to discuss in detail the main physical aspects of the fast ignition concept and understand the current state and prospects of studies in this direction.

Gus'kov, S. Yu., E-mail: guskov@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2013-01-15T23:59:59.000Z

222

First Hot Electron Measurements in Near-ignition Scale Hohlraums on the National Ignition Facility  

SciTech Connect (OSTI)

On the National Ignition Facility (NIF), the hot electrons generated in laser heated hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to meet requirements for ignition and to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ignition scaled hohlraums heated by 96-192 NIF laser beams are presented.

Dewald, E L; Suter, L J; Thomas, C; Hunter, S; Meeker, D; Meezan, N; Glenzer, S H; Bond, E; Kauffman, R L; Kilkenny, J; Landen, O

2009-10-08T23:59:59.000Z

223

The National Ignition Facility National Ignition Campaign Short Pulse Lasers High-Average-Power Laser  

E-Print Network [OSTI]

#12;The National Ignition Facility National Ignition Campaign Short Pulse Lasers High hole shields SSD, Polarization smoothing Improvements in ignition point designs have reduced laser Campaign NIF-0905-11310 09EIM/dj 1997 1.7 MJ ignition point design 0.5 0.4 0.3 0.2 0.1 0 0 0.5 1 1.5 Laser

224

Effect of engine operating parameters and fuel characteristics on diesel engine emissions  

E-Print Network [OSTI]

To examine the effects of using synthetic Fischer-Tropsch (FT) diesel fuel in a modern compression ignition engine, experiments were conducted on a MY 2002 Cummins 5.9 L diesel engine outfitted with high pressure, common ...

Acar, Joseph, 1977-

2005-01-01T23:59:59.000Z

225

Laser Spark Distribution and Ignition System  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

partners interested in implement- ing United States Patent Number 7,421,166 entitled "Laser Spark Distribution and Ignition System." Disclosed in this patent is NETL's laser...

226

Physics Guidelines for the Compact Ignition Tokamak  

Science Journals Connector (OSTI)

The Compact Ignition Tokamak Program / Proceedings of the Seveth Topical Meeting on the Technology of Fusion Energy (Reno, Nevada, June 15–19, 1986)

J. Sheffield; R. A. Dory; W. A. Houlberg; N. A. Uckan; M. Bell; P. Colestock; J. Hosea; S. Kaye; M. Petravic; D. Post; S. D. Scott; K. M. Young; K. H. Burrell; N. Ohyabu; R. Stambaugh; M. Greenwald; P. Liewer; D. Ross; C. Singer; H. Weitzner

227

Achieving laser ignition using zero index metamaterials  

Science Journals Connector (OSTI)

The possibility of laser ignition using zero index metamaterials (ZIM) is investigated theoretically. Using this method, multiple laser beams can be focused automatically regardless of...

Zhai, Tianrui; Shi, Jinwei; Chen, Shujing; Liu, Dahe; Zhang, Xinping

2011-01-01T23:59:59.000Z

228

Laser Fusion: The Uncertain Road to Ignition  

Science Journals Connector (OSTI)

In early 2014, the U.S. National Ignition Facility announced that it had achieved a fusion reaction that produced net positive energy. Fusion scientists have applauded that...

Rose, Melinda

2014-01-01T23:59:59.000Z

229

National Ignition Facility | National Nuclear Security Administration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

other ICF high energy density facilities leading to demonstrate fusion ignition and thermonuclear burn in the laboratory. The NIF is also being used to support basic science and...

230

Fast Ignition Program in Japan "Progress of Fast Ignition Project; FIREX"  

E-Print Network [OSTI]

1 Fast Ignition Program in Japan "Progress of Fast Ignition Project; FIREX" Fast Ignition.4 Fusion , Laser Astrophysics, EUV, and so on are main projects Laser Spectroscopy NIFS, Okayama Univ., High Pressure EOS AIST Tokyo Inst. Tech Laser Acceleration, Terahertz Coherent X-Ray JAEA KPRI Fusion

231

Assessment of Potential for Ion Driven Fast Ignition  

E-Print Network [OSTI]

mm radius ion beams Fast Ignition (laser or fast ion pulse)deg half cone angle Fast Ignition (laser or fast ion pulse)ion beam pulses for fast ignition, laser generated ion beams

2005-01-01T23:59:59.000Z

232

Engineering  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Engineering Engineering Engineering1354608000000EngineeringSome of these resources are LANL-only and will require Remote Access./No/Questions? 667-5809library@lanl.gov Engineering Some of these resources are LANL-only and will require Remote Access. Key Resources Reference Standards Data Sources Organizations Journals Key Resources Engineering Village Includes Engineering Index (Ei) and Compendex Knovel Handbooks, databases, and eBooks integrated with analytical and search tools IEEE Xplore Full text access to technical literature, standards, and conference proceedings in engineering and technology SPIE Digital Library Full-text papers from SPIE journals and proceedings published since 1998; subject coverage includes optics, photonics, electronic imaging, visual information processing, biomedical optics, lasers, and

233

An Experimental Study into the Ignition of Methane and Ethane Blends in a New Shock-tube Facility  

E-Print Network [OSTI]

AN EXPERIMENTAL STUDY INTO THE IGNITION OF METHANE AND ETHANE BLENDS IN A NEW SHOCK-TUBE FACILITY A Thesis by CHRISTOPHER JOSEPH ERIK AUL Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2009 Major Subject: Mechanical Engineering AN EXPERIMENTAL STUDY INTO THE IGNITION OF METHANE AND ETHANE BLENDS IN A NEW SHOCK-TUBE FACILITY A Thesis...

Aul, Christopher Joseph Erik

2011-02-22T23:59:59.000Z

234

Detailed Analysis and Control Issues of Homogeneous Charge Compression Ignition (HCCI)  

SciTech Connect (OSTI)

Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work.

Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Espinosa-Loza, Francisco; Dibble, Robert

2002-08-25T23:59:59.000Z

235

Ignition of Isomers of Pentane: An Experimental and Kinetic Modeling Study  

SciTech Connect (OSTI)

Hydrocarbon ignition is an important element in many practical combustion systems, including internal combustion engines, detonations, pulse combustors, and flame initiation. The rapid compression machine (RCM) is used frequently to study the kinetics of hydrocarbon autoignition [e.g., 1-7], since the reactive gas temperatures and time histories are similar to those seen in automotive engines during Diesel ignition and end gas autoignition leading to engine knock in spark-ignition engines. The RCM provides a rich environment for study of the theory of hydrocarbon oxidation, including degenerate chain branching, alkylperoxy radical isomerization and effects of thermal feedback [8]. The literature of hydrocarbon oxidation studies in the RCM has been summarized recently [9,10], and many classes of fuels have been studied. Detailed kinetic modeling is another tool available to study hydrocarbon oxidation in the RCM [4,11]. The aim of the present work is to determine experimentally the influence of variations in fuel molecular structure on autoignition, and to use a kinetic model to understand the reasons for those variations. This study is unique in that while other studies have addressed variations in pressure and equivalence ratio on ignition [11], this work addresses effects of variations in fuel molecular structure for all of the isomers of a single fuel formula, pentane, in a RCM. The three isomers of pentane possess many of the structural elements that determine such autoignition characteristics as octane number and variability in cool flame production, so this study will benefit our efforts to describe these effects.

Ribaucour, M; Minetti, R; Sochet, L R; Curran, H J; Pitz, W J; Westbrook, C K

2000-01-11T23:59:59.000Z

236

Homogeneous Charge Compression Ignition Free Piston Linear Alternator  

SciTech Connect (OSTI)

An experimental and theoretical investigation of a homogeneous charge compression ignition (HCCI) free piston powered linear alternator has been conducted to determine if improvements can be made in the thermal and conversion efficiencies of modern electrical generator systems. Performance of a free piston engine was investigated using a rapid compression expansion machine and a full cycle thermodynamic model. Linear alternator performance was investigated with a computer model. In addition linear alternator testing and permanent magnet characterization hardware were developed. The development of the two-stroke cycle scavenging process has begun.

Janson Wu; Nicholas Paradiso; Peter Van Blarigan; Scott Goldsborough

1998-11-01T23:59:59.000Z

237

Institute of Laser Engineering Osaka University  

E-Print Network [OSTI]

? ·Since the fuel contains no central hot spark, the Fast Ignition can ignite with 1/10 of laser energyH. Azechi Director Institute of Laser Engineering Osaka University Fusion Power Associates Washington DC 2009.12.2-3 ILE OSAKA 1 Laser Fusion in Japan: Combat with global warming Haunting face crying

238

from Wikipedia Institute of Laser Engineering  

E-Print Network [OSTI]

1 from Wikipedia ILE OSAKA H. Azechi Director Institute of Laser Engineering Osaka University NIF Technical Symposium Livermore 2009.5.28 Inertial Fusion Energy in Japan #12;ILE OSAKA Fast Ignition Realization Experiment (FIREX) Project 2 Implosion Fast heating Ignition/Burn ·Proof-of-concept: Scalable

239

The National Ignition Facility: The Path to a Carbon-Free Energy Future  

SciTech Connect (OSTI)

The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centers on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.

Stolz, C J

2011-03-16T23:59:59.000Z

240

Engineering  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Engineering Engineering Lawrence Livermore National Laboratory Home Technologies Core Competencies Showcase Careers Partnerships About Advanced Manufacturing Developing high-performance materials, devices, components, and assemblies enabled by innovative design tools and novel manufacturing techniques Learn more Applied Electromagnetics Supporting the development of electromagnetic systems that are pervasive and paramount to the greater National Security community. Learn more Data Sciences Enabling better decisions through the development and application of state-of-the-art techniques in machine learning, statistics, and decision sciences Learn more Precision Engineering Embracing determinism to guide rigorous design, construction, and metrology of mechatronic systems, instruments, and manufactured components

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Advances in inertial confinement fusion at the National Ignition Facility (NIF)  

Science Journals Connector (OSTI)

The 192-beam National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational and conducting experiments. NIF, the flagship facility of the U.S. Inertial Confinement Fusion (ICF) Program, will achieve high-energy-density conditions never previously obtained in the laboratory—temperatures over 100 million K, densities of 1000 g/cm3, and pressures exceeding 100 billion atmospheres. Such conditions exist naturally only in the interiors of the stars and during thermonuclear burn. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. To date, the NIF laser has demonstrated all pulse shape, beam quality, energy, and other specifications required to meet the ignition challenge. On March 10, 2009, the NIF laser delivered 1.1 MJ of ultraviolet laser energy to target chamber center, approximately 30 times more energy than any previous facility. The ignition program at NIF is the National Ignition Campaign (NIC), a national collaboration for ignition experimentation with participation from General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Laser Energetics (LLE). The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on fusion as a viable energy option. A particular energy concept under investigation is the LIFE (Laser Inertial Fusion Energy) scheme. The LIFE engine is inherently safe, minimizes proliferation concerns associated with the nuclear fuel cycle, and can provide a sustainable carbon-free energy generation solution in the 21st century. This talk will describe NIF and its potential as a user facility and an experimental platform for high-energy-density science, NIC, and the LIFE approach for clean, sustainable energy.

Edward I. Moses

2010-01-01T23:59:59.000Z

242

Advances in Inertial Confinement Fusion at the National Ignition Facility (NIF)  

SciTech Connect (OSTI)

The 192-beam National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational and conducting experiments. NIF, the flagship facility of the U.S. Inertial Confinement Fusion (ICF) Program, will achieve high-energy-density conditions never previously obtained in the laboratory - temperatures over 100 million K, densities of 1,000 g/cm3, and pressures exceeding 100 billion atmospheres. Such conditions exist naturally only in the interiors of the stars and during thermonuclear burn. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. To date, the NIF laser has demonstrated all pulse shape, beam quality, energy, and other specifications required to meet the ignition challenge. On March 10, 2009, the NIF laser delivered 1.1 MJ of ultraviolet laser energy to target chamber center, approximately 30 times more energy than any previous facility. The ignition program at NIF is the National Ignition Campaign (NIC), a national collaboration for ignition experimentation with participation from General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Laser Energetics (LLE). The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on fusion as a viable energy option. A particular energy concept under investigation is the LIFE (Laser Inertial Fusion Energy) scheme. The LIFE engine is inherently safe, minimizes proliferation concerns associated with the nuclear fuel cycle, and can provide a sustainable carbon-free energy generation solution in the 21st century. This talk will describe NIF and its potential as a user facility and an experimental platform for high-energy-density science, NIC, and the LIFE approach for clean, sustainable energy.

Moses, E

2009-10-15T23:59:59.000Z

243

Combustion optimization in a hydrogen-enhanced lean burn SI engine  

E-Print Network [OSTI]

Lean operation of spark ignition (SI) automotive engines offers attractive performance incentives. Lowered combustion temperatures inhibit NO[sub]x pollutant formation while reduced manifold throttling minimizes pumping ...

Goldwitz, Joshua A. (Joshua Arlen), 1980-

2004-01-01T23:59:59.000Z

244

Predicting the behavior of a lean-burn hydrogen-enhanced engine concept  

E-Print Network [OSTI]

(cont.) Lean operation of a spark ignition (SI) internal combustion engine (ICE) offers attractive performance incentives. Lowered combustion temperatures inhibit formation of nitrogen oxides (NOx), while reduced intake ...

Ivanic, Žiga, 1978-

2004-01-01T23:59:59.000Z

245

Speciated Engine-Out Organic Gas Emissions from a PFI-SI Engine Operating on Ethanol/Gasoline Mixtures  

E-Print Network [OSTI]

Engine-out HC emissions from a PFI spark ignition engine were measured using a gas chromatograph and a flame ionization detector (FID). Two port fuel injectors were used respectively for ethanol and gasoline so that the ...

Kar, Kenneth

246

FY2001 Progress Report for the Spark Ignition Direct Injection R&D Program  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

SPARK IGNITION, SPARK IGNITION, DIRECT INJECTION ENGINE R&D 2 0 0 1 A N N U A L P R O G R E S S R E P O R T U.S. Department of Energy Energy Efficiency and Renewable Energy Office of Transportation Technologies A C K N O W L E D G E M E N T We would like to express our sincere appreciation to Argonne National Laboratory and Computer Systems Management, Inc., for their artistic and technical contributions in preparing and publishing this report. In addition, we would like to thank all our program participants for their contributions to the programs and all the authors who prepared the project abstracts that comprise this report. U.S. Department of Energy Office of Transportation Technologies 1000 Independence Avenue, S.W. Washington, DC 20585-0121 FY 2001 Progress Report for the Spark Ignition Direct Injection R&D Program

247

Inertial Confinement Fusion: steady progressInertial Confinement Fusion: steady progress towards ignition and high gaintowards ignition and high gain  

E-Print Network [OSTI]

, Vilamoura, Portugal. #12;Main route to ignition: indirect laser drive with central hot-spot ignition and ignition implosion DT capsule hohlraum case ~ 30 m of Au (or Pb)µ laser beams 5.5 mm 9.5 mm ablator DT ice constantly accumulated on currently operating non- ignition-scale lasers at Rochester, LANL, ILE, UK

248

Fast Ignition: Nuclear Fusion with UltraFast Ignition: Nuclear Fusion with Ultra--intenseintense LASERsLASERs  

E-Print Network [OSTI]

pellet composed of deuterium and tritium. In the fast ignition regime a secondy p g g p p g g laser, nearly limitless, fuel source. Fusion via Fast Ignition MethodUltra-Intense Laser Research atFusion via Direct Drive Method U Strathclyde IgnitionCompression IgnitionCompression · Very intense lasers (shown

Strathclyde, University of

249

Hot electron measurements in ignition relevant Hohlraums on the National Ignition Facility  

SciTech Connect (OSTI)

On the National Ignition Facility (NIF), hot electrons generated in laser heated Hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the time integrated FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ignition scaled Hohlraums heated by 96-192 NIF laser beams are presented.

Dewald, E. L.; Thomas, C.; Hunter, S.; Divol, L.; Meezan, N.; Glenzer, S. H.; Suter, L. J.; Bond, E.; Celeste, J.; Bradley, D.; Bell, P.; Kauffman, R. L.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kline, J. L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kilkenny, J. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

2010-10-15T23:59:59.000Z

250

National Ignition Facility & Photon Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

energy needs has been a decades-long scientific and engineering quest. While a self-sustaining fusion burn has been achieved for brief periods under experimental conditions,...

251

Characterisation of laser ignition in hydrogen–air mixtures in a combustion bomb  

Science Journals Connector (OSTI)

Laser-induced spark ignition of lean hydrogen–air mixtures was experimentally investigated using nanosecond pulses generated by Q-switched Nd:YAG laser (wavelength 1064 nm) at initial pressure of 3 MPa and temperature 323 K in a constant volume combustion chamber. Laser ignition has several advantages over conventional ignition systems especially in internal combustion engines, hence it is necessary to characterise the combustion phenomena from start of plasma formation to end of combustion. In the present experimental investigation, the formation of laser plasma by spontaneous emission technique and subsequently developing flame kernel was measured. Initially, the plasma propagates towards the incoming laser. This backward moving plasma (towards the focusing lens) grows much faster than the forward moving plasma (along the direction of laser). A piezoelectric pressure transducer was used to measure the pressure rise in the combustion chamber. Hydrogen–air mixtures were also ignited using a spark plug under identical experimental conditions and results are compared with the laser ignition ones.

Dhananjay Kumar Srivastava; Martin Weinrotter; Kurt Iskra; Avinash Kumar Agarwal; Ernst Wintner

2009-01-01T23:59:59.000Z

252

Inertial-confinement fusion with fast ignition  

Science Journals Connector (OSTI)

...achieve ignition and thermonuclear burn. For a fusion power plant, gains...the ratio of the thermonuclear energy to the initial...released by the thermonuclear burn in unit mass...compressed spherical fusion fuel. Higher gain...

1999-01-01T23:59:59.000Z

253

History of the approach to ignition  

Science Journals Connector (OSTI)

...International Thermonuclear Experimental Reactor...recommended. plasma|fusion|tokamak|ignition...density plasma to thermonuclear temperatures...in the quest for fusion power. Such an...temperatures of thermonuclear interest, this...for an acceptable fusion reactor. By a...

1999-01-01T23:59:59.000Z

254

Effects of temperature on laser diode ignition  

Science Journals Connector (OSTI)

In this paper, the effects of temperature on laser diode ignition and the resulting consequences were discussed in detail through theoretical analysis, experiments and numerical calculations. The results indicated that the output power of laser diode decreases and the wavelength of laser redshifts with elevated working temperature under a certain condition. The threshold conditions of ignition for powders are easily satisfied with increase in ambient temperature. While the temperature reaches a high enough level, ignition can occur and also the self-combustion or thermal induced explosion can do, even if laser power is very low. Therefore, it is of great importance to carefully control the working temperature of laser diode and the ambient temperature of powder system, and in the meanwhile, to install necessary insurance apparatus in order to ensure the normal and safe operation of the ignition system.

Shi-Biao Xiang; Xu Xiang; Chang-Gen Feng

2009-01-01T23:59:59.000Z

255

Laser-induced ignition by optical breakdown  

Science Journals Connector (OSTI)

This paper is an experimental work of the applied methodical character in which as an attempt to optimize a laser ignition system a systematic study of the best incoupling geometry for the employed Nd:YAG laser w...

E. Schwarz; I. Muri; J. Tauer; H. Kofler; E. Wintner

2010-06-01T23:59:59.000Z

256

Ignition with Laser Break-Down  

Science Journals Connector (OSTI)

It is considered that ignition with laser break-down is one of the applications of solid-state lasers. This paper shows basic experimental results indicating the advantages of laser...

Furutani, Hirohide; Saito, Takeshi

257

Focus issue introduction: Laser Ignition Conference  

Science Journals Connector (OSTI)

The purpose of this feature issue is to share information on laser ignition and related sciences and technologies. This feature offers five papers in the field that cover aspects of...

Taira, Takunori; Furutani, Hirohide; Guo, Chunlei; Wintner, Ernst; Akamatsu, Fumiteru; Lucht, Robert; Washio, Kunihiko

2014-01-01T23:59:59.000Z

258

Confinement scaling and ignition in tokamaks  

SciTech Connect (OSTI)

A drift wave turbulence model is used to compute the scaling and magnitude of central electron temperature and confinement time of tokamak plasmas. The results are in accord with experiment. Application to ignition experiments shows that high density (1 to 2) . 10/sup 15/ cm/sup -3/, high field, B/sub T/ > 10 T, but low temperature T approx. 6 keV constitute the optimum path to ignition.

Perkins, F.W.; Sun, Y.C.

1985-10-01T23:59:59.000Z

259

The National Ignition Facility: Status of Construction  

E-Print Network [OSTI]

Bruce Warner Deputy Associate Director, NIF Programs Lawrence Livermore National Laboratory October 11, 2005 #12;NIF-0605-10997 27EIM/cld NIF-0605-10997-L2 27EIM/cld P LLNLLLNL P9266 #12;NIF-0605-10997 27EIM/cld NIF-0605-10997-L28 27EIM/cld P LLNLLLNL National Ignition FacilityNational Ignition Facility P9292 San

260

National Ignition Facility Cryogenic Target Systems Interim Management Plan  

SciTech Connect (OSTI)

Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize the National Ignition Facility (NIF) Cryogenic Target Handling Systems (NCTS) Program, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NCTS. Preparation of a Program Execution Plan (PEP) for NCTS has been initiated, and a current draft is provided as Attachment 1 to this document. The National Ignition Facility is a multi-megajoule laser facility being constructed at Lawrence Livermore National Laboratory (LLNL) by the National Nuclear Security Administration (NNSA) in the Department of Energy (DOE). Its primary mission is to support the Stockpile Stewardship Program (SSP) by performing experiments studying weapons physics, including fusion ignition. NIF also supports the missions of weapons effects, inertial fusion energy, and basic science in high-energy-density physics. NIF will be operated by LLNL under contract to the University of California (UC) as a national user facility. NIF is a low-hazard, radiological facility, and its operation will meet all applicable federal, state, and local Environmental Safety & Health (ES&H) requirements. The NCTS Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope, cost, and schedule. The NIF Director controls the NIF Cryogenic Target Systems Interim Management Plan. Overall scope content and execution schedules for the High Energy Density Physics Campaign (SSP Campaign 10) are currently undergoing rebaselining and will be brought into alignment with resources expected to be available throughout the NNSA Future Years National Security Plan (FYNSP). The revised schedule for delivering this system will be decided at the national level, based on experiment campaign requirement dates that will be derived through this process. The current milestone date for achieving indirect-drive ignition on the NIF is December 2010. Maintaining this milestone requires that the cryogenic systems be complete and available for fielding experiments early enough that the planned experimental campaigns leading up to ignition can be carried out. The capability of performing non-ignition cryogenic experiments is currently required by March 2006, when the NIF's first cluster of beams is operational. Plans for cryogenic and non-cryogenic experiments on the NIF are contained in NNSA's Campaign 10 Program Plans for Ignition (MTE 10.1) and High Energy Density Sciences (MTE 10.2). As described in this document, the NCTS Program Manager is responsible for managing NIF Cryogenic Target Systems development, engineering, and deployment. Through the NIF Director, the NCTS Program Manager will put in place an appropriate Program Execution Plan (draft attached) at a later time consistent with the maturing and funding these efforts. The PEP will describe management methods for carrying out these activities.

Warner, B

2002-04-25T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Department of Mechanical Engineering RESEARCH PROJECT  

E-Print Network [OSTI]

#12;Department of Mechanical Engineering OVERVIEW · Combustion of alternative biofuels for automotive · Combustion properties of biofuels, including biodiesel and biojet fuels · Shock tube ignition experiments for a New Generation of Aircrafts · Jets Manipulation and

Barthelat, Francois

262

Engineering  

Science Journals Connector (OSTI)

... and, as a result, connected information regarding the use of indicators on internal combustion engines is not readily obtainable. The author, who designed that most useful instrument, the ... in the manipulation of these instruments. His survey is limited to the combined piston, spring and pencil-lever types, and traces their development from the original instrument devised by ...

1939-03-11T23:59:59.000Z

263

Engineering Engineering  

E-Print Network [OSTI]

Engineering Engineering Technology & A T P E N N S T A T E 2 0 1 0 ­ 2 0 1 1 #12;2 Join us at penn state! Since 1896, Penn State has been a leader in engineering and engineering technology education varieties of engineering and engineering technology majors found anywhere in the United States. This means

Maroncelli, Mark

264

Quantum Tunneling Affects Engine Performance  

Science Journals Connector (OSTI)

It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. ... In this Letter we have demonstrated that a detailed understanding of the chemical dynamics of elementary reactions, including quantum tunneling, is necessary for an accurate description of the performance of compression-ignition engine models, and that something as fundamental as quantum tunneling corrections could make a noticeable difference on such a complex model. ... combustion and emissions in diesel engines. ...

Sibendu Som; Wei Liu; Dingyu D. Y. Zhou; Gina M. Magnotti; Raghu Sivaramakrishnan; Douglas E. Longman; Rex T. Skodje; Michael J. Davis

2013-05-29T23:59:59.000Z

265

BIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air Pollution, Intext Educational Publishers, 1973  

E-Print Network [OSTI]

engines, now somewhat dated.) 6. M. Khovakh (general editor) Motor Vehicle Engines. English translation, Akademiai Kaido:Budapest, 1974. (A monograph on heat transfer in spark-ignition and diesel enginesBIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air

Goldwasser, Shafi

266

The role of the National Ignition Facility in energy production from inertial fusion  

Science Journals Connector (OSTI)

...in IFE attractive. inertial fusion energy|laser fusion|ignition (lasers)|thermonuclear gain|National Ignition Facility...inertial fusion energy; laser fusion; ignition (lasers); thermonuclear gain; National Ignition Facility...

1999-01-01T23:59:59.000Z

267

Direct numerical simulation of ignition front propagation in a constant volume with temperature inhomogeneities. I. Fundamental analysis and diagnostics  

SciTech Connect (OSTI)

The influence of thermal stratification on autoignition at constant volume and high pressure is studied by direct numerical simulation (DNS) with detailed hydrogen/air chemistry with a view to providing better understanding and modeling of combustion processes in homogeneous charge compression-ignition engines. Numerical diagnostics are developed to analyze the mode of combustion and the dependence of overall ignition progress on initial mixture conditions. The roles of dissipation of heat and mass are divided conceptually into transport within ignition fronts and passive scalar dissipation, which modifies the statistics of the preignition temperature field. Transport within ignition fronts is analyzed by monitoring the propagation speed of ignition fronts using the displacement speed of a scalar that tracks the location of maximum heat release rate. The prevalence of deflagrative versus spontaneous ignition front propagation is found to depend on the local temperature gradient, and may be identified by the ratio of the instantaneous front speed to the laminar deflagration speed. The significance of passive scalar mixing is examined using a mixing timescale based on enthalpy fluctuations. Finally, the predictions of the multizone modeling strategy are compared with the DNS, and the results are explained using the diagnostics developed. (author)

Chen, Jacqueline H.; Hawkes, Evatt R.; Sankaran, Ramanan [Reacting Flow Research Department, Combustion Research Facility, Sandia National Laboratories, P.O. Box 969 MS 9051, Livermore, CA 94551-0969 (United States); Mason, Scott D. [Lockheed Martin Corporation, Sunnyvale, CA 94089 (United States); Im, Hong G. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125 (United States)

2006-04-15T23:59:59.000Z

268

Analytical model for fast-shock ignition  

SciTech Connect (OSTI)

A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ?4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ?0.3??micron and the shock ignitor energy weight factor about 0.25.

Ghasemi, S. A., E-mail: abo.ghasemi@yahoo.com; Farahbod, A. H. [Plasma Physics Research School, NSTRI, North Kargar Avenue, Tehran (Iran, Islamic Republic of); Sobhanian, S. [Department of Physics, Tabriz University, Tabriz (Iran, Islamic Republic of)

2014-07-15T23:59:59.000Z

269

Thermonuclear supernova simulations with stochastic ignition  

E-Print Network [OSTI]

We apply an ad hoc model for dynamical ignition in three-dimensional numerical simulations of thermonuclear supernovae assuming pure deflagrations. The model makes use of the statistical description of temperature fluctuations in the pre-supernova core proposed by Wunsch & Woosley (2004). Randomness in time is implemented by means of a Poisson process. We are able to vary the explosion energy and nucleosynthesis depending on the free parameter of the model which controls the rapidity of the ignition process. However, beyond a certain threshold, the strength of the explosion saturates and the outcome appears to be robust with respect to number of ignitions. In the most energetic explosions, we find about 0.75 solar masses of iron group elements. Other than in simulations with simultaneous multi-spot ignition, the amount of unburned carbon and oxygen at radial velocities of a few 1000 km/s tends to be reduced for an ever increasing number of ignition events and, accordingly, more pronounced layering results.

W. Schmidt; J. C. Niemeyer

2005-10-14T23:59:59.000Z

270

Effects of Fuel Ignition Quality on Critical Equivalence Ratio for Autoignition  

Science Journals Connector (OSTI)

This hypothesis is based on the work of Musculus et al.,(2) who introduced the concept of a “critical” equivalence ratio (?), below which fuel in localized regions of the chamber is a potential source for incomplete combustion. ... The evaporative steam cooling system, used to maintain water jacket temperatures of the engine in the standard CFR engine design,(12) was replaced with an 8 L 1000 W refrigerated/heating circulator. ... Musculus et al.,(2) who first presented the concept of critical ?, stated that “UHC emissions may arise from jets that ignite before EOI (negative ignition dwell) if the mixtures near the injector become too lean either to autoignite in the time available or to support propagation of the downstream reaction zone into the near-injector region.” ...

Gregory K. Lilik; André L. Boehman

2013-02-11T23:59:59.000Z

271

Laser ignition of a heterogeneous nickel-aluminum system  

Science Journals Connector (OSTI)

The ignition of a heterogeneous nickel—aluminum system by laser radiation is investigated experimentally. The ignition characteristics are investigated as a function of ... the samples. It is established that the...

Yu. S. Naiborodenko; V. M. Filatov

272

National Ignition Facility & Photon Science NIF AT A GLANCe  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

& Photon Science NIF AT A GLANCe the national ignition Facility at a glance The National Ignition Facility (NIF) is the world's largest laser system, housed in a 10-story building...

273

Numerical simulation of laser ignition of a liquid fuel film  

Science Journals Connector (OSTI)

Numerical simulations were used to examine a set of interrelated physicochemical processes involved in the ignition of a liquid fuel film by a low-power laser beam. The delay time of ignition of a liquid fuel fil...

G. V. Kuznetsov; P. A. Strizhak

2010-08-01T23:59:59.000Z

274

National Ignition Facility & Photon Science NIF Fun Facts  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

7 National Ignition Facility & Photon Science NIF Fun Facts niF Fun Facts The National Ignition Facility (NIF), became operational in march 2009. Planning began in the early 1990s,...

275

Target Visualization at the National Ignition Facility  

SciTech Connect (OSTI)

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.

Potter, D

2011-11-21T23:59:59.000Z

276

The velocity campaign for ignition on NIF  

SciTech Connect (OSTI)

Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 {+-} 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 {+-} 5 {mu}m/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 {+-} 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our 'first pass' tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].

Callahan, D. A.; Meezan, N. B.; Glenzer, S. H.; MacKinnon, A. J.; Benedetti, L. R.; Bradley, D. K.; Celeste, J. R.; Celliers, P. M.; Dixit, S. N.; Doeppner, T.; Dzentitis, E. G.; Glenn, S.; Haan, S. W.; Haynam, C. A.; Hicks, D. G.; Hinkel, D. E.; Jones, O. S.; Landen, O. L.; London, R. A.; MacPhee, A. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-05-15T23:59:59.000Z

277

Ignition of deuterium-tritium fuel targets  

DOE Patents [OSTI]

Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

Musinski, D.L.; Mruzek, M.T.

1991-08-27T23:59:59.000Z

278

Load expansion of naphtha multiple premixed compression ignition (MPCI) and comparison with partially premixed compression ignition (PPCI) and conventional diesel combustion (CDC)  

Science Journals Connector (OSTI)

Abstract In previous studies, multiple premixed compression ignition (MPCI) has been proposed as a novel combustion concept in gasoline compression ignition engines which has great potential to achieve high thermal efficiency and low emissions simultaneously. MPCI mode was realized by a sequence of “spray–combustion–spray–combustion” around the compression top dead center (TDC). This study is aimed for the high load expansion of naphtha MPCI. In addition, the study investigated advantages and disadvantages of MPCI compared with partially premixed compression ignition (PPCI) and conventional diesel combustion (CDC). Engine operating range successfully reached indicated mean effective pressure (IMEP) of 1.4 MPa with high thermal efficiency, low emissions and acceptable combustion noise by the optimization of the injection parameters and the intake management. For MPCI, earlier combustion phasing was possible even at the high load operation compared with PPCI and CDC. This was attributed to the separated heat release characteristics and pressure rise rate process. The divided pressure rise rate process caused considerably low maximum pressure rise rate (MPRR) characteristics such as 0.8 MPa/deg at IMEP 1.4 MPa condition. The earlier combustion phasing led to the higher thermal efficiency characteristics of MPCI combustion compared with PPCI and CDC. This was attributed to the lower exhaust heat loss characteristics. However, high level of hydrocarbon (HC) and carbon monoxide (CO) emissions with low combustion stability at the low load operation were considered as severe challenges to overcome.

Kihyun Kim; Zhi Wang; Buyu Wang; Shijin Shuai; Hongqiang Yang; Choongsik Bae

2014-01-01T23:59:59.000Z

279

DOE/EIS-0236, Oakland Operations Office, National Ignition Facility...  

Energy Savers [EERE]

DOEEIS-0236, Oakland Operations Office, National Ignition Facility Final Supplemental Environmental Impact Statement to the Stockpile Stewardship and Management Programmatic...

280

Shock Ignition: A New Approach to High Gain Inertial Confinement Fusion on the National Ignition Facility  

Science Journals Connector (OSTI)

Shock ignition, an alternative concept for igniting thermonuclear fuel, is explored as a new approach to high gain, inertial confinement fusion targets for the National Ignition Facility (NIF). Results indicate thermonuclear yields of ?120–250??MJ may be possible with laser drive energies of 1–1.6 MJ, while gains of ?50 may still be achievable at only ?0.2??MJ drive energy. The scaling of NIF energy gain with laser energy is found to be G?126E??(MJ)0.510. This offers the potential for high-gain targets that may lead to smaller, more economic fusion power reactors and a cheaper fusion energy development path.

L. J. Perkins; R. Betti; K. N. LaFortune; W. H. Williams

2009-07-23T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Scaling laws for ignition at the National Ignition Facility from first principles  

Science Journals Connector (OSTI)

We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements.

Baolian Cheng; Thomas J. T. Kwan; Yi-Ming Wang; Steven H. Batha

2013-10-07T23:59:59.000Z

282

A comparative study of laser ignition and spark ignition with gasoline–air mixtures  

Science Journals Connector (OSTI)

Abstract The ignition probability and minimum ignition energy (MIE) of premixed gasoline–air mixture for different equivalence ratio was experimentally studied using a nanosecond pulse at 532 nm and 1064 nm from a Q-switched Nd:YAG laser in a constant-volume combustion chamber (CVCC) The result was compared with the spark ignition. The initial pressure and temperature of the mixture was 0.1 MP and 363 K, respectively. The research indicates that within the flammable range, the probability increases when the ignition energy increases and the distribution of MIE with the equivalence ratios is U-shape for both laser and spark ignition. For laser ignition with 532 nm, when the incident energy is higher than 110 mJ or the absorbed energy is high than 31 mJ, 100% of ignition could be obtained within equivalence ratios of 0.8–1.6. For 1064 nm it is 235 mJ and 30 mJ. To get the same ignition probability of mixture with identical equivalence ratio, the incident energy of 1064 nm is twice more than the incident energy of 532 nm, while the absorbed energy values are virtually the same. It indicates that significant wavelength dependence is expected for the initial free electrons but irrelevant for the process of absorbing energy. The initial free electrons are produced from impurities in gasoline–air mixture because the intensity in the focus (1012 W/cm2) is too low to ionize gas molecules via the multi-photon ionization process, which requires higher irradiance (?1014 W/cm2). The MIE obtained with a laser-spark ignition is greater than that measured by electrical sparks. The MIE for laser ignition was obtained at equivalence ratio of 1.0 both of 532 nm and 1064 nm, and it was 13.5 mJ and 9.5 mJ, respectively. But for spark ignition, the MIE is 3.76 mJ with equivalence ratio of 1.6. What?s more, laser ignition extends the lean flammability limit from 0.8 to 0.6.

Cangsu Xu; Donghua Fang; Qiyuan Luo; Jian Ma; Yang Xie

2014-01-01T23:59:59.000Z

283

Experimental basis for laser-plasma interactions in ignition hohlraums at the National Ignition Facility  

SciTech Connect (OSTI)

A series of laser plasma interaction experiments at OMEGA (LLE, Rochester) using gas-filled hohlraums shed light on the behavior of stimulated Raman scattering and stimulated Brillouin scattering at various plasma conditions encountered in indirect drive ignition designs. We present detailed experimental results that quantify the density, temperature, and intensity thresholds for both of these instabilities. In addition to controlling plasma parameters, the National Ignition Campaign relies on optical beam smoothing techniques to mitigate backscatter. We show that polarization smoothing is effective at controlling backscatter. These results provide an experimental basis for forthcoming experiments on National Ignition Facility.

Froula, D H; Divol, L; London, R A; Berger, R L; Doeppner, T; Meezan, N B; Ralph, J; Ross, J S; Suter, L J; Glenzer, S H

2009-11-12T23:59:59.000Z

284

Laser-Plasma Coupling with Ignition-Scale Targets: New Regimes and Frontiers on the National Ignition Facility  

Science Journals Connector (OSTI)

It is very exciting that the National Ignition Facility (NIF) is now operational and being used to irradiate ignition-scale hohlraums. As discussed in the last ... Summer School in Physics on the topic of laser-p...

William L. Kruer

2013-01-01T23:59:59.000Z

285

Ignition and Flame Quenching of Quiescent Fuel Mists  

Science Journals Connector (OSTI)

...Ignition and Flame Quenching of Quiescent Fuel Mists D. R. Ballal A. H. Lefebvre A...the ignition of quiescent multidroplet fuel mists which assumes that chemical reaction...spark, of an adequate concentration of fuel vapour in the ignition zone. From analysis...

1978-01-01T23:59:59.000Z

286

Status of the National Ignition Campaign Prof. R. Paul Drake  

E-Print Network [OSTI]

Ignition Campaign has the goal of producing net en- ergy gain in a laser-fusion system. I have been keeping Status of the National Ignition Campaign Prof. R. Paul Drake Joint Seminar with Atmospheric progress on the National Ignition Campaign, from a recent conference. This includes a discussion

Shyy, Wei

287

Planning for the National Ignition Campaign on NIF Presentation to  

E-Print Network [OSTI]

yields>1 MJ (an ignition margin >1) with the expected precision of target experiments, laser performance by melting with the first shock ·We predict an ignition margin >1 at the point design laser energy #12;A CH that roll up to set the ignition conditions ~150 lower parameters 1D quantities, e.g: Peak Laser Power Foot

288

Inertial Confinement Fusion Ignition and High Yield Campaign  

E-Print Network [OSTI]

to redirect High Average Power Lasers to be synergistic with NIF ignition and other defense missions #12 · Predicted gains (fusion energy produced/laser energy input) have increased · Direct drive ignition shows) Project has begun · Will add two high-energy petawatt lasers for OMEGA for advanced backlighting and fast-ignition

289

Status of Experiments on National Ignition Facility Presented to  

E-Print Network [OSTI]

into the hohlraum temperature range for ignition experiments at 280-300 eV · The laser, diagnostic, targetStatus of Experiments on National Ignition Facility Presented to 31st Annual Meeting and Symposium Associates 4NIF­1110-20542.ppt #12;National Ignition Campaign goals Moses - 31st Annual Meeting and Symposium

290

Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility  

SciTech Connect (OSTI)

Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes 'day one' NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

Terry, Matthew R.; Perkins, L. John; Sepke, Scott M. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States)

2012-11-15T23:59:59.000Z

291

National Ignition Facility Title II Design Plan  

SciTech Connect (OSTI)

This National Ignition Facility (NIF) Title II Design Plan defines the work to be performed by the NIF Project Team between November 1996, when the U.S. Department of Energy (DOE) reviewed Title I design and authorized the initiation of Title H design and specific long-lead procurements, and September 1998, when Title 11 design will be completed.

Kumpan, S

1997-03-01T23:59:59.000Z

292

Impacts assessment for the National Ignition Facility  

SciTech Connect (OSTI)

This report documents the economic and other impacts that will be created by the National Ignition Facility (NIF) construction and ongoing operation, as well as the impacts that may be created by new technologies that may be developed as a result of NIF development and operation.

Bay Area Economics

1996-12-01T23:59:59.000Z

293

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-Print Network [OSTI]

a safe, secure, and reliable nuclear weapons stockpile without underground testing. Science-based weapons and certify the stockpile without nuclear testing. The National Ignition Facility (NIF) extends HEDP under extreme conditions that approach the high energy density (HED) environments found in a nuclear

294

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-Print Network [OSTI]

, and reliability of the Nation's nuclear weapons without nuclear testing. The program provides this capability models that are used to assess and certify the stockpile without nuclear testing. The National Ignition that approach the high-energy density (HED) environments found in a nuclear explosion. Virtually all

295

UCRL-PRES-225531 National ignition facility  

E-Print Network [OSTI]

Title Page UCRL-PRES-225531 #12;National ignition facility #12;NIF is 705,000 #12;NIF laser system #12;NIF us 885 #12;NIF-0506-11956 Laser bay 2 #12;Switchyard 2 #12;Target chamber in the air #12;Target chamber #12;Target chamber national geographic #12;Target chamber inside #12;Warehouse of laser

296

Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller  

E-Print Network [OSTI]

Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies and low emission levels. HCCI combustion is achieved through...

Abdelgawad, Marwa

2012-07-16T23:59:59.000Z

297

Fuel Effects on Low Temperature Combustion in a Light-Duty Diesel Engine  

Broader source: Energy.gov [DOE]

Six different fuels were investigated to study the influence of fuel properties on engine out emissions and performance of low temperature premixed compression ignition combustion light-duty HSDI engines

298

Groundbreaking at National Ignition Facility | National Nuclear Security  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Groundbreaking at National Ignition Facility | National Nuclear Security Groundbreaking at National Ignition Facility | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > Groundbreaking at National Ignition Facility Groundbreaking at National Ignition Facility May 29, 1997 Livermore, CA Groundbreaking at National Ignition Facility

299

X-ray driven implosions at ignition relevant velocities on the National Ignition Facility  

SciTech Connect (OSTI)

Backlit convergent ablator experiments on the National Ignition Facility [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] are indirect drive implosions that study the inflight dynamics of an imploding capsule. Side-on, backlit radiography provides data used by the National Ignition Campaign to measure time-dependent properties of the capsule ablator including its center of mass radius, velocity, and unablated mass. Previously, Callahan [D. A. Callahan et al., Phys. Plasmas 19, 056305 (2012)] and Hicks [D. H. Hicks et al., Phys. Plasmas 19, 122702 (2012)] reported backlit convergent ablator experiments demonstrating velocities approaching those required for ignition. This paper focuses on implosion performance data in the “rocket curve” plane, velocity vs. ablator mass. These rocket curve data, along with supporting numerical simulations, show that the nominal 195 ?m-thick ignition capsule would reach the ignition velocity goal V = 370 km/s with low ablator mass remaining–below the goal of M = 0.25 mg. This finding led to experiments with thicker capsule ablators. A recent symmetry capsule experiment with a 20 ?m thicker capsule driven by 520 TW, 1.86 MJ laser pulse (along with a companion backlit convergent ablator experiment) appears to have demonstrated V?350 km/s with ablator mass remaining above the ignition goal.

Meezan, N. B.; MacKinnon, A. J.; Hicks, D. G.; Dewald, E. L.; Tommasini, R.; Le Pape, S.; Döppner, T.; Ma, T.; Farley, D. R.; Kalantar, D. H.; Di Nicola, P.; Callahan, D. A.; Robey, H. F.; Thomas, C. A.; Prisbrey, S. T.; Jones, O. S.; Milovich, J. L.; Clark, D. S.; Eder, D. C.; Schneider, M. B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2013-05-15T23:59:59.000Z

300

Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility  

SciTech Connect (OSTI)

Point design targets have been specified for the initial ignition campaign on the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. The targets contain D-T fusion fuel in an ablator of either CH with Ge doping, or Be with Cu. These shells are imploded in a U or Au hohlraum with a peak radiation temperature set between 270 and 300 eV. Considerations determining the point design include laser-plasma interactions, hydrodynamic instabilities, laser operations, and target fabrication. Simulations were used to evaluate choices, and to define requirements and specifications. Simulation techniques and their experimental validation are summarized. Simulations were used to estimate the sensitivity of target performance to uncertainties and variations in experimental conditions. A formalism is described that evaluates margin for ignition, summarized in a parameter the Ignition Threshold Factor (ITF). Uncertainty and shot-to-shot variability in ITF are evaluated, and sensitivity of the margin to characteristics of the experiment. The formalism is used to estimate probability of ignition. The ignition experiment will be preceded with an experimental campaign that determines features of the design that cannot be defined with simulations alone. The requirements for this campaign are summarized. Requirements are summarized for the laser and target fabrication.

Haan, S. W.; Lindl, J. D.; Callahan, D. A.; Clark, D. S.; Salmonson, J. D.; Hammel, B. A.; Atherton, L. J.; Cook, R. C.; Edwards, M. J.; Glenzer, S.; Hamza, A. V.; Hatchett, S. P.; Hinkel, D. E.; Ho, D. D.; Jones, O. S.; Landen, O. L.; MacGowan, B. J.; Marinak, M. M.; Milovich, J. L.; Moses, E. I. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2011-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A study of ignition of oil shale and char  

SciTech Connect (OSTI)

The ignition characteristics of Fushun, Maoming and Jordan oil shale samples have been determined experimentally by using thermogravimetric analyzer (TGA) and CO/CO{sub 2} analyzer. Their chars have been investigated, too. Two ignition mechanisms for oil shale and shale char are suggested. One is called heterogeneous, according to which, the ignition takes place on the surface of the oil shale and/or shale char sample. Another is called homogeneous, the ignition occurring in the gas phase surrounding the particles. The ignition mechanism occurred mainly depends on the condition of the combustion, physical properties of samples and the rate of volatile release. The experimental equations of ignition for three kinds of oil shale and their char particles (Fushun, Maoming and Jordan) are given. The difference of ignition temperatures for these oil shale and their char particles are compared in terms of chemical compositions and physical properties.

Min, L.; Changshan, L. (Fushun Research Institute of Petroleum and Petrochemicals, Sinopec (CN))

1989-01-01T23:59:59.000Z

302

Flame kernel characterization of laser ignition of natural gas–air mixture in a constant volume combustion chamber  

Science Journals Connector (OSTI)

In this paper, laser-induced ignition was investigated for compressed natural gas–air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air–fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel–air mixture was investigated under different relative air–fuel ratios (?=1.2?1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas–air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.

Dhananjay Kumar Srivastava; Kewal Dharamshi; Avinash Kumar Agarwal

2011-01-01T23:59:59.000Z

303

The National Ignition Facility (NIF) and the National Ignition Campaign (NIC)  

SciTech Connect (OSTI)

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8-MJ, 500-TW of 351-nm third-harmonic, ultraviolet light. On March 10, 2009, total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments includes diagnostics, a cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational, integrated into the facility, and ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and Fast Ignition concepts. Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics and materials science. The NIC will develop the full set of capabilities required to operate NIF as a major national and international user facility. A solicitation for NIF frontier science experiments is planned for summer 2009. This paper summarizes the design, performance, and status of NIF and plans for the NIF ignition experimental program. A brief summary of the overall NIF experimental program is also presented.

Moses, E

2009-09-17T23:59:59.000Z

304

The National Ignition Facility and the Promise of Inertial Fusion Energy  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

Moses, E I

2010-12-13T23:59:59.000Z

305

Examination of the high load limit of an HCCI engine  

E-Print Network [OSTI]

The implementation of homogenous charge compression ignition (HCCI) to gasoline engines is constrained by many factors. This work examines constrains imposed by nitric oxide (NOx) emission and by the need to maintain a ...

Anderson, Nathan (Nathan Charles)

2008-01-01T23:59:59.000Z

306

Translation of dilution tolerance for gasoline SI engine  

E-Print Network [OSTI]

There are a variety of fuel improvement strategies being developed for spark ignition engines which use dilution. Many of these technologies use a combination of different diluents. It is impractical in optimizing these ...

Niekamp, Troy S. (Troy Steven)

2013-01-01T23:59:59.000Z

307

Modeling of Combustion Processes in Internal Combustion Engines  

Science Journals Connector (OSTI)

Improving internal combustion engines (ICE) and increasing the quality of operation are linked with the necessity of maximally increasing the degree of compression. For ICE with spark ignition (otto cycle), th...

V. A. Vinokurov; V. A. Kaminskii; V. A. Frost…

2000-11-01T23:59:59.000Z

308

Configuring the National Ignition Facility for direct-drive experiments  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is a project whose primary mission is to provide an above-ground experimental capability for maintaining nuclear competence and weapons effects simulation, and to pursue the achievement of fusion ignition utilizing solid state lasers as the energy driver. In this facility a large number of laser beams are focused onto a small target located at the center of a spherical target chamber. The laser energy is delivered in a few billionths of a second, raising the temperature and density of the nuclear materials in the target to levels where significant thermonuclear energy is released. The thermonuclear reaction proceeds very rapidly, so that the target materials remain confined by their own inertia during the thermonuclear reaction. This type of approach is called inertial confinement fusion (ICF). The proposed project is described in a conceptual design report (CDR) that was released in May 1994. Early in FY95, a collaboration between the University of Rochester and the Lawrence Livermore National Laboratory was established to study reconfiguring the NIF to accommodate direct-drive experiments. The present paper is a report to the scientific community, primarily the scientists and engineers working on the design of the NIF. It represents results from work in progress, specifically work completed by the end of the second quarter FY95. This report has two main sections. The first describes the target requirements on the laser drive, and the second part describes how the NIF laser can be configured to accommodate both indirect and direct drive. The report includes a description of the scientific basis for these conclusions. Though a complete picture does not exist, the present understanding is sufficient to conclude that the primary target requirements and laser functional requirements for indirect and direct drive are quite compatible. It is evidently straightforward to reconfigure the NIF to accommodate direct and indirect drive.

Eimerl, D. [ed.

1995-07-01T23:59:59.000Z

309

HCCI Engine Optimization and Control  

SciTech Connect (OSTI)

The goal of this project was to develop methods to optimize and control Homogeneous-Charge Compression Ignition (HCCI) engines, with emphasis on diesel-fueled engines. HCCI offers the potential of nearly eliminating IC engine NOx and particulate emissions at reduced cost over Compression Ignition Direct Injection engines (CIDI) by controlling pollutant emissions in-cylinder. The project was initiated in January, 2002, and the present report is the final report for work conducted on the project through December 31, 2004. Periodic progress has also been reported at bi-annual working group meetings held at USCAR, Detroit, MI, and at the Sandia National Laboratories. Copies of these presentation materials are available on CD-ROM, as distributed by the Sandia National Labs. In addition, progress has been documented in DOE Advanced Combustion Engine R&D Annual Progress Reports for FY 2002, 2003 and 2004. These reports are included as the Appendices in this Final report.

Rolf D. Reitz

2005-09-30T23:59:59.000Z

310

Ignition on the National Ignition Facility: a path towards inertial fusion energy  

Science Journals Connector (OSTI)

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8?MJ, 500?TW of light at the third-harmonic, ultraviolet light of 351?nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0?MJ of light at the fundamental wavelength of 1053?nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium–tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications.The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization.Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed (Lindl 1998 Inertial Confinement Fusion: the Quest for Ignition and Energy Gain Using Indirect Drive (New York: American Institute of Physics)) and has a high probability of success. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and fast ignition concepts (Tabak et al 1994 Phys. Plasmas 1 1626–34, Tabak et al 2005 Phys. Plasmas 12 057305). Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics and materials science.This paper summarizes the design, performance and status of NIF, experimental plans for NIC, and will present laser inertial confinement fusion–fission energy (LIFE) as a path to achieve carbon-free sustainable energy.

Edward I. Moses

2009-01-01T23:59:59.000Z

311

Innovative coal-fueled diesel engine injector  

SciTech Connect (OSTI)

The purpose of this research investigation was to develop an electronic coal water slurry injection system in conjunction with the Thermal Ignition Combustion System (TICS) concept to achieve autoignition of CWS at various engine load and speed conditions without external ignition sources. The combination of the new injection system and the TICS is designed to reduce injector nozzle spray orifice wear by lowering the peak injection pressure requirements. (VC)

Badgley, P.; Doup, D.

1991-05-01T23:59:59.000Z

312

National Ignition Facility & Photon Science - Bringing Star Power to Earth  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NIF Go NIF Go LLNL Logo Lawrence Livermore National Laboratory LLNL Home NIF Home LIFE Home Jobs Site Map Contact News Press Releases In the News Status Update Media Assistance About Us National Ignition Facility About NIF How NIF Works The Seven Wonders of NIF Building NIF An Engineering Marvel NIFFY Early Light Collaborators Status Visiting NIF Missions National Security Energy for the Future Understanding the Universe People The People of NIF Awards NIF Professor Sabbatical Opportunities NIF Online Store Programs National Ignition Campaign How to Make a Star (ICF) Target Physics Target Fabrication Cryogenic Target System Diagnostics Participants Photon Science & Applications Advanced Optics Advanced Radiography Directed Energy Fusion Energy Inertial Fusion Energy How IFE Works Science at the Extremes

313

Laser-plasma interactions for fast ignition  

E-Print Network [OSTI]

In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multi-dimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the compa...

Kemp, A J; Debayle, A; Johzaki, T; Mori, W B; Patel, P K; Sentoku, Y; Silva, L O

2013-01-01T23:59:59.000Z

314

Multiple laser pulse ignition method and apparatus  

DOE Patents [OSTI]

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures. 18 figs.

Early, J.W.

1998-05-26T23:59:59.000Z

315

Multiple laser pulse ignition method and apparatus  

DOE Patents [OSTI]

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

Early, James W. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

316

The National Ignition Campaign: status and progress  

Science Journals Connector (OSTI)

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been operational since March 2009 and a variety of experiments have been completed and many more are planned in support of NIF's mission areas: national security, fundamental science, and fusion energy. NIF capabilities and infrastructure are in place to support all of its missions with nearly 60 x-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. The NIF has also been qualified for the use of tritium and other special materials as well as to perform high-yield experiments and classified experiments. Implosions with record indirect-drive neutron yield of 7.5 ? 1014 neutrons have been achieved. NIF, a Nd?:?Glass laser facility, is routinely operating at 1.6 MJ of ultraviolet (3?) light on target with very high reliability. It recently reached its design goal of 1.8 MJ and 500 TW of 3? light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress towards achieving ignition. Other experiments have been completed in support of high-energy science, materials equation of state, and materials strength. In all cases, records of extreme temperatures and pressures, highest neutron yield and highest energy densities have been achieved. This paper describes the unprecedented experimental capabilities of the NIF and the results achieved so far on the path towards ignition.

E.I. Moses; the NIC Collaborators

2013-01-01T23:59:59.000Z

317

Laser-induced ignition modeling of HMX  

Science Journals Connector (OSTI)

Abstract The laser-induced ignition response of HMX has been investigated using a detailed numerical model. The model is one-dimensional, fully transient, and solves the conservation equations for both the condensed and gas phases. The condensed phase representation includes radiation absorption, solid-phase transitions, melting, evaporation, and distributed semi-global decomposition kinetics. The gas phase utilizes a detailed kinetic mechanism to predict species formation and destruction. Ignition occurs in the gas phase and the flame propagates back toward the surface of the HMX in what is known as the ‘snap-back’ effect. The model then transitions to steady-state combustion. Calculations were performed in which the solid HMX is irradiated with heat fluxes ranging from 50 to 1600 W/cm2. Results are compared to empirical data for the laser-induced ignition of HMX. Good agreement with these data and other steady-state data (burning rate, surface temperature, melt thickness) provide the necessary validation of the developed model.

Karl V. Meredith; Matthew L. Gross; Merrill W. Beckstead

2014-01-01T23:59:59.000Z

318

The piston dynamics under knock situation of diesel dual fuel engine: a numerical study  

Science Journals Connector (OSTI)

A compression ignition engine fueled by natural gas or Diesel Dual Fuel (DDF) engine is a promising engine for the future of a high oil price. Unfortunately, the DDF engine knocks easily: this leads to damage of pistons. So, the understanding of the ... Keywords: diesel dual fuel engine, knock, mixed-lubrication, modelling, piston secondary motion, simulation

Krisada Wannatong; Somchai Chanchaona; Surachai Sanitjai

2007-01-01T23:59:59.000Z

319

Ignitor with stable low-energy thermite igniting system  

DOE Patents [OSTI]

A stable compact low-energy igniting system in an ignitor utilizes two components, an initiating charge and an output charge. The initiating charge is a thermite in ultra-fine powder form compacted to 50-70% of theoretical maximum density and disposed in a cavity of a header of the ignitor adjacent to an electrical ignition device, or bridgewire, mounted in the header cavity. The initiating charge is ignitable by operation of the ignition device in a hot-wire mode. The output charge is a thermite in high-density consoladated form compacted to 90-99% of theoretical maximum density and disposed adjacent to the initiating charge on an opposite end thereof from the electrical ignition device and ignitable by the initiating charge. A sleeve is provided for mounting the output charge to the ignitor header with the initiating charge confined therebetween in the cavity.

Kelly, Michael D. (West Alexandria, OH); Munger, Alan C. (Miamisburg, OH)

1991-02-05T23:59:59.000Z

320

Capsule performance optimization in the National Ignition Campaign  

SciTech Connect (OSTI)

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Landen, O. L.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Michel, P.; Milovich, J.; Munro, D. H.; Robey, H. F.; Spears, B. K.; Thomas, C. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2010-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Capsule Performance Optimization in the National Ignition Campaign  

SciTech Connect (OSTI)

A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Landen, O L; MacGowan, B J; Haan, S W; Edwards, J

2009-10-13T23:59:59.000Z

322

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

traditional power plant. A clean technology can also reduceOn the other hand, “clean” technology advancements can alsoA third consideration of clean technologies is whether it is

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

323

Simulation of turbulent flames relevant to spark-ignition engines  

E-Print Network [OSTI]

- merous interesting and fruitful discussions. In addition, the comput- ing help I received from Mr Peter Benie and the staff at the Cambridge High Performance Computing Service is gratefully acknowledged. This work would not have been possible without...

Ahmed, Irufan

2014-04-29T23:59:59.000Z

324

Simulation study of two-stroke cycle compression ignition engines  

E-Print Network [OSTI]

for mixing as shown in Fig. 3. The scavenging model used in this work is based on Dedeoglu's et af (5] experiments and Benson's er ul (13) analytical model for both loop and cross scavenged systems. The diesel combustion submodel is perhaps the weakest... equivalence ratio of the fuel/air mixture. The contribution of this to the increase in the internal energy of the system accounts for the chemical energy input of the fuel. 26 Diesel Combustion Model: The complete simulation of the actual com- bustion...

Kishan, Sandeep

2012-06-07T23:59:59.000Z

325

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

particulates (soot). Even wind power can have the undesiredsuch as solar and wind power, and offshore technologies willcost of solar and wind power presents a grand opportunity

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

326

High Efficiency GDI Engine Research, with Emphasis on Ignition...  

Broader source: Energy.gov (indexed) [DOE]

Light-tight Fiber-Optic Launch Enclosure Metal-shielded Fiber Optic Big Sky Laser Head Spatial filter Technical Accomplishments Free-Air Delivered Laser 13 Higher rate of...

327

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

fraction of energy converted in the case of solar panels orsolar energy, wind energy, and the earth’s heat through respective advances in nuclear fission, hydroelectric dams, photovoltaic solar panels,

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

328

High-Efficiency Clean Combustion Design for Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs.

329

High Efficiency GDI Engine Research, with Emphasis on Ignition...  

Broader source: Energy.gov (indexed) [DOE]

plate) Complicated tradeoff between real combustion (i.e. phasing and duration) and heat loss to the combustion chamber walls GDI Concepts 11 Technical accomplishments...

330

High Efficiency GDI Engine Research, with Emphasis on Ignition Systems  

Broader source: Energy.gov [DOE]

2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

331

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

as solar-charged hydrogen fuel cells were allowed to becomee.g. wind-generated hydrogen fuel cell hybrid vehicle) can

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

332

ENGINEERING FEATURES OF THE FUSION IGNITION RESEARCH EXPERIMENT (FIRE)  

E-Print Network [OSTI]

fusion energy program. It has a major radius of 2 m, and a minor radius of 0.525 m. The general with antenna through the large ports. The major features are shown in Figure 1. -TF Coils and Global Structure coils. Each vessel quadrant has a large mid plane port, angled ports above and below the mid

333

Development scenario for passenger-car diesel engines with optimised: Combustion processes to meet future emission standards  

Science Journals Connector (OSTI)

The main reason why the modern supercharged direct-injection diesel engine is so successful as a means of propelling passenger cars is because it is more efficient than spark-ignition engines in nearly every o...

Jörn Kahrstedt; Kai Behnk; Ansgar Sommer; Thorsten Wormbs

2003-10-01T23:59:59.000Z

334

High resolution simulations of ignition capsule designs for the National Ignition Facility  

SciTech Connect (OSTI)

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and - most recently - experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as two thousand, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to two hundred on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode twelve hundred have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

Clark, D S; Haan, S W; Cook, A W; Edwards, M J; Hammel, B A; Koning, J M; Marinak, M M

2011-02-17T23:59:59.000Z

335

Clearing the air with natural gas engines  

SciTech Connect (OSTI)

This article examines the increased popularity of natural gas vehicles which has spurred engine designers to manipulate fuel-air ratios, compression ratios, ignition timing, and catalytic converters in ways to minimize exhaust pollutants. The topics of the article include reducing pollutants, high-octane engineering, diesel to natural gas, and the two-fuel choice.

O'Connor, L.

1993-10-01T23:59:59.000Z

336

Review of the National Ignition Campaign 2009-2012  

SciTech Connect (OSTI)

The National Ignition Campaign (NIC) was a multi-institution effort established under the National Nuclear Security Administration of DOE in 2005, prior to the completion of the National Ignition Facility (NIF) in 2009. The scope of the NIC was the planning and preparation for and the execution of the first 3 yr of ignition experiments (through the end of September 2012) as well as the development, fielding, qualification, and integration of the wide range of capabilities required for ignition. Besides the operation and optimization of the use of NIF, these capabilities included over 50 optical, x-ray, and nuclear diagnostic systems, target fabrication facilities, experimental platforms, and a wide range of NIF facility infrastructure. The goal of ignition experiments on the NIF is to achieve, for the first time, ignition and thermonuclear burn in the laboratory via inertial confinement fusion and to develop a platform for ignition and high energy density applications on the NIF. The goal of the NIC was to develop and integrate all of the capabilities required for a precision ignition campaign and, if possible, to demonstrate ignition and gain by the end of FY12. The goal of achieving ignition can be divided into three main challenges. The first challenge is defining specifications for the target, laser, and diagnostics with the understanding that not all ignition physics is fully understood and not all material properties are known. The second challenge is designing experiments to systematically remove these uncertainties. The third challenge is translating these experimental results into metrics designed to determine how well the experimental implosions have performed relative to expectations and requirements and to advance those metrics toward the conditions required for ignition. This paper summarizes the approach taken to address these challenges, along with the progress achieved to date and the challenges that remain. At project completion in 2009, NIF lacked almost all the diagnostics and infrastructure required for ignition experiments. About half of the 3 yr period covered in this review was taken up by the effort required to install and performance qualify the equipment and experimental platforms needed for ignition experiments. Ignition on the NIF is a grand challenge undertaking and the results presented here represent a snapshot in time on the path toward that goal. The path forward presented at the end of this review summarizes plans for the Ignition Campaign on the NIF, which were adopted at the end of 2012, as well as some of the key results obtained since the end of the NIC.

Lindl, John; Landen, Otto; Edwards, John; Moses, Ed [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Collaboration: NIC Team

2014-02-15T23:59:59.000Z

337

HEC-DPSSL 2012 Workshop, Directions: National Ignition Facility...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Road Keep left at the fork Destination will be on the right Directions to Lawrence Livermore National Laboratory and the National Ignition Facility can be found on the...

338

Modeling the Number of Ignitions Following an Earthquake: Developing...  

Office of Environmental Management (EM)

Developing Prediction Limits for Overdispersed Count Data Authors: Elizabeth J. Kelly and Raymond N. Tell Modeling the Number of Ignitions Following an Earthquake:...

339

Synthesizing aluminum particles towards controlling electrostatic discharge ignition sensitivity  

SciTech Connect (OSTI)

Aluminum particles were synthesized with shell thicknesses ranging from 2.7 to 8.3 nm and a constant diameter of 95 nm. These fuel particles were combined with molybdenum trioxide particles and the electrostatic discharge (ESD) sensitivity of the mixture was measured. Results show ignition delay increased as the alumina shell thickness increased. These results correlated with electrical resistivity measurements of the mixture which increased with alumina concentration. A model was developed using COMSOL for ignition of a single Al particle. The ignition delay in the model was consistent with the experimental results suggesting that the primary ESD ignition mechanism is joule heating.

Eric S. Collins; Jeffery P. Gesner; Michelle L. Pantoya; Michael A. Daniels

2014-02-01T23:59:59.000Z

340

Pulsed Laser Ignition Thresholds of Energetic Multilayer Foils  

Science Journals Connector (OSTI)

Ignition thresholds for energetic multilayer foils comprised of aluminum (Al) and platinum (Pt) layers are presented as a function of foil properties for laser pulse durations of 100...

McDonald, Joel P; Picard, Yoosuf N; Yalisove, Steven M; Adams, David P

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

HEC-DPSSL 2012 Workshop, NIF Tour: National Ignition Facility...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Deadline: August 10, 2012 Lawrence Livermore National Laboratory is home to the National Ignition Facility (NIF). NIF is a national resource a unique experimental facility...

342

Effects of Ignition Quality and Fuel Composition on Critical...  

Broader source: Energy.gov (indexed) [DOE]

Multi-cylinder, turbocharged, common rail, direct injection study in which high ignition quality fuel was found avoid NO X , PM, THC and CO emissions while maintaining...

343

High power fiber delivery for laser ignition applications  

Science Journals Connector (OSTI)

The present contribution provides a concise review of high power fiber delivery research for laser ignition applications. The fiber delivery requirements are discussed in terms of exit...

Yalin, Azer P

2013-01-01T23:59:59.000Z

344

Advanced Natural Gas Reciprocating Engine(s)  

SciTech Connect (OSTI)

The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cycle efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.

Pike, Edward

2014-03-31T23:59:59.000Z

345

Combustion characteristics of coal fuels in adiabatic diesel engines  

SciTech Connect (OSTI)

An experimental investigation was conducted to determine the combustion characteristics of coal fuels in adiabatic diesel engines. For this purpose engine testing was carried out by the fumigation of fine coal powder to the intake of an insulated and uncooled single cylinder diesel engine. The engine tests conducted include three types of fuels - Diesel fuel No. 2 (DF-2), Dual fuel (DF-2 + Coal), and Coal fuel. Excellent combustion characteristics of coal fuels were obtained in the present work in an adiabatic engine operating at high temperatures. The ''thermal ignition'' concept uncovered in this investigation led to a hot ''ignition chamber'' which provided ignition of the coal fuel. The high temperature engine with the ''ignition chamber'' permitted engine operation on 100% coal fuel without any external ignition aids or compression ignition. With the addition of a glow plug, the coal fueled engine was successfully cold started. For the coal fueled engine tests, analysis of cylinder pressure data showed rapid heat release rates, shorter combustion duration and very fast burning of coal powder fuel. Preliminary results of the apparent indicated cycle efficiency calculated from the heat release data, indicate that 100% coal powder fueled engine has higher cycle efficiency than DF-2 fueled engine in an adiabatic configuration. The problems encountered during the engine tests include: variation in the engine speed and load due to non-uniform coal flow rate by the coal feed system, contamination of the lubricating oil with fine coal powder, and wear of conventional piston rings. However, these problems can be solved with an improved coal feed system and wear resistant ceramic materials for the piston rings. 33 refs.

Kamo, R.; Kakwani, R.M.; Woods, M.E.; Valdmanis, E.

1986-06-01T23:59:59.000Z

346

Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester with KIVA-3V  

SciTech Connect (OSTI)

Discusses the use of KIVA-3V to develop a model that reproduces ignition behavior inside the Ignition Quality Tester, which measures the ignition delay of low-volatility fuels.

Bogin, G. E. Jr.; DeFilippo, A.; Chen, J. Y.; Chin, G.; Luecke, J.; Ratcliff, M. A.; Zigler, B. T.; Dean, A. M.

2010-05-01T23:59:59.000Z

347

Investigation of proton focusing and conversion efficiency for proton fast ignition  

E-Print Network [OSTI]

as a step towards laser fusion ignition,” nature, vol. 412,laser in order for the ignition laser to be absorbed in areason being that the ignition laser energy would otherwise

Bartal, Teresa Jean

2012-01-01T23:59:59.000Z

348

Electron generation and transport in intense relativistic laser-plasma interactions relevant to fast ignition ICF  

E-Print Network [OSTI]

as a step towards laser fusion ignition, Nature, 412 (2001),tip. Full scale fast ignition laser systems are envisionedmodified. Full scale fast ignition laser systems of 100 kJ

Ma, Tammy Yee Wing

2010-01-01T23:59:59.000Z

349

Uncooled two-stroke gas engine for heat pump drive  

SciTech Connect (OSTI)

This paper describes the design and analysis of a family of natural gas fueled, uncooled, two-stroke, lean burn, thermal-ignition engines. The engines were designed specifically to meet the requirements dictated by the commercial heat pump application. The engines have a power output ranging from 15 to 100 kW; a thermal efficiency of 36 percent; a mean time between failure greater than 3 years; and a life expectancy of 45,000 hours. To meet these specifications a family of very simple, uncooled, two-stroke cycle engines were designed which have no belts, gears or pumps. The engines utilize crankcase scavenging, lubrication, stratified fuel introduction to prevent raw fuel from escaping with the exhaust gas, use of and ceramic rolling contact bearings. The Thermal Ignition Combustion System (TICS) is used for ignition to enable the engines to operate with a lean mixture and eliminate spark plug erosion. 4 refs., 16 figs.

Badgley, P.; McNulty, D.; Woods, M.

1990-01-01T23:59:59.000Z

350

Natural Gas-optimized Advanced Heavy-duty Engine  

E-Print Network [OSTI]

Natural Gas-optimized Advanced Heavy-duty Engine Transportation Research PIER Transportation of natural gas vehicles as a clean alternative is currently limited to smaller engine displacements and spark ignition, which results in lower performance. A large displacement natural gas engine has

351

Effect of Ethanol on Blending Stability and Diesel Engine Emissions  

Science Journals Connector (OSTI)

Effect of Ethanol on Blending Stability and Diesel Engine Emissions ... Industrial & Engineering Chemistry Research2013 52 (44), 15504-15508 ... This article describes the effects of hydroxylated biodiesel (castor oil methyl ester – COME) on the properties, combustion, and emissions of butanol–diesel blends used within compression ignition engines. ...

Magín Lapuerta; Octavio Armas; Reyes García-Contreras

2009-07-28T23:59:59.000Z

352

A Concept Exploration Program in Fast Ignition Inertial Fusion — Final Report  

SciTech Connect (OSTI)

The Fast Ignition (FI) approach to Inertial Confinement Fusion (ICF) holds particular promise for fusion energy because the independently generated compression and ignition pulses allow ignition with less compression, resulting in (potentially) higher gain. Exploiting this concept effectively requires an understanding of the transport of electrons in prototypical geometries and at relevant densities and temperatures. Our consortium, which included General Atomics (GA), The Ohio State University (OSU), the University of California, San Diego (UCSD), University of California, Davis (UC-Davis), and Princeton University under this grant (~$850K/yr) and Lawrence Livermore National Laboratory (LLNL) under a companion grant, won awards in 2000, renewed in 2005, to investigate the physics of electron injection and transport relevant to the FI concept, which is crucial to understand electron transport in integral FI targets. In the last two years we have also been preparing diagnostics and starting to extend the work to electron transport into hot targets. A complementary effort, the Advanced Concept Exploration (ACE) program for Fast Ignition, was funded starting in 2006 to integrate this understanding into ignition schemes specifically suitable for the initial fast ignition attempts on OMEGA and National Ignition Facility (NIF), and during that time these two programs have been managed as a coordinated effort. This result of our 7+ years of effort has been substantial. Utilizing collaborations to access the most capable laser facilities around the world, we have developed an understanding that was summarized in a Fusion Science & Technology 2006, Special Issue on Fast Ignition. The author lists in the 20 articles in that issue are dominated by our group (we are first authors in four of them). Our group has published, or submitted 67 articles, including 1 in Nature, 2 Nature Physics, 10 Physical Review Letters, 8 Review of Scientific Instruments, and has been invited to give numerous talks at national and international conferences (including APS-DPP, IAEA, FIW). The advent of PW capabilities – at Rutherford Appleton Lab (UK) and then at Titan (LLNL) (2005 and 2006, respectively), was a major step toward experiments in ultra-high intensity high-energy FI relevant regime. The next step comes with the activation of OMEGA EP at LLE, followed shortly by NIF-ARC at LLNL. These capabilities allow production of hot dense material for electron transport studies. In this transitional period, considerable effort has been spent in developing the necessary tools and experiments for electron transport in hot and dense plasmas. In addition, substantial new data on electron generation and transport in metallic targets has been produced and analyzed. Progress in FI detailed in §2 is related to the Concept Exploration Program (CEP) objectives; this section is a summary of the publications and presentations listed in §5. This work has benefited from the synergy with work on related Department of Energy (DOE) grants, the Fusion Science Center and the Fast Ignition Advanced Concept Exploration grant, and from our interactions with overseas colleagues, primarily at Rutherford Appleton Laboratory in the UK, and the Institute for Laser Engineering in Japan.

Stephens, Richarad Burnite [General Atomics] [General Atomics; Freeman, Richard R. [The Ohio State University] [The Ohio State University; Van Woekom, L. D. [The Ohio State University] [The Ohio State University; Key, M. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; MacKinnon, Andrew J. [Lawrence Livermore National Laboratory] [Lawrence Livermore National Laboratory; Wei, Mingsheng [General Atomics] [General Atomics

2014-02-27T23:59:59.000Z

353

Scope for reducing the concentrations of NO and CH /SUB X/ in forechamber flame ignition of a fuel mixture  

SciTech Connect (OSTI)

This article discusses the reduction of concentrations of toxic components in exhaust gases resulting from using the forechamber ignition method in gasoline engines containing homogeneous mixtures. A method was devised to calculate the pressure and average temperature in the combustion chamber, as well as the temperatures and concentrations for 11 equilibrium combustion products in individual local zones of the combustion chamber with allowance for the Mache effect, and also the true values for the molecular-change coefficients and the loss of heat of combustion due to dissociation, and the NO formation kinetics indicated by Zel'dovich's mechanism. It is concluded that the production of toxic components can be reduced in an engine with forechamber flame ignition and a high compression ratio only by using deliberate stratification and a displacing ring to prevent the fuel from entering peripheral and dead zones of the chamber before and after combustion.

Mekhtiev, R.I.

1983-09-01T23:59:59.000Z

354

Advanced Natural Gas Reciprocating Engine(s)  

SciTech Connect (OSTI)

Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work has consisted of both modeling and single cylinder engine experiments to quantify DIGN performance. The air handling systems of natural gas engines dissipate a percentage of available energy as a result of both flow losses and turbomachinery inefficiencies. An analytical study was initiated to increase compressor efficiency by employing a 2-stage inter-cooled compressor. Caterpillar also studied a turbo-compound system that employs a power turbine to recover energy from the exhaust gases for improved engine efficiency. Several other component and system investigations were undertaken during the final phase of the program to reach the ultimate ARES goals. An intake valve actuation system was developed and tested to improve engine efficiency, durability and load acceptance. Analytical modeling and materials testing were performed to evaluate the performance of steel pistons and compacted graphite iron cylinder head. Effort was made to improve the detonation sensing system by studying and comparing the performance of different pressure sensors. To reduce unburned hydrocarbon emissions, different camshafts were designed and built to investigate the effect of exhaust valve opening timing and value overlap. 1-D & 3-D coupled simulation was used to study intake and exhaust manifold dynamics with the goal of reducing load in-balance between cylinders. Selective catalytic reduction with on-board reductant generation to reduce NOx emissions was also engine tested. An effective mean to successfully deploy ARES technologies into the energy markets is to deploy demonstration projects in the field. In 2010, NETL and Caterpillar agreed to include a new “opportunity fuel” deliverable and two field demonstrations in the ARES program. An Organic Rankine Cycle system was designed with production intent incorporating lessons learned from the Phase II demonstration. Unfortunately, business conditions caused Caterpillar to cancel this demonstration in 2011. Nonetheless, Caterpillar partnered with a local dealer to deploy an ARES class engine using syngas from a biomass gasifier as

Kwok, Doris; Boucher, Cheryl

2009-09-30T23:59:59.000Z

355

Neural control of fast nonlinear systems Application to a turbocharged SI engine with VCT  

E-Print Network [OSTI]

Ignition (SI) engines. In this context, an efficient control of the air actuators (throttle, Turbo Timing (VCT) for air scavenging from the intake to the exhaust. Moreover, VCT decreases pollutants of the ignition coils, fuel injectors and air actuators. The air actuator controllers generally used are PID

Paris-Sud XI, Université de

356

Status of the National Ignition Facility project  

SciTech Connect (OSTI)

The ultimate goal of worldwide research in inertial confinement fusion (ICF) is to develop fusion as an inexhaustible, economic, environmentally safe source of electric power. Following nearly thirty years of laboratory and underground fusion experiments, the next step toward this goal is to demonstrate ignition and propagating burn of fusion fuel in the laboratory. The National Ignition Facility(NIF) Project is being constructed at Lawrence Livermore National Laboratory (LLNL), for just this purpose. NIF will use advanced Nd-glass laser technology to deliver 1.8 MJ of 0.35-um laser light in a shaped pulse, several nanoseconds in duration, achieving a peak power of 500 TW. A national community of U.S. laboratories is participating in this project, now in its final design phase. Franceand the United Kingdom are collaborating on development of required technology under bilateral agreements with the US. This paper presents thestatus of the laser design and development of its principal components and optical elements.

Paisner, J.A.; Lowdermilk, W.H.; Boyes, J.D.; Sorem, M.S.; Soures, J.M.

1997-04-01T23:59:59.000Z

357

Catalytic igniters and their use to ignite lean hydrogen-air mixtures  

DOE Patents [OSTI]

A catalytic igniter which can ignite a hydrogen-air mixture as lean as 5.5% hydrogen with induction times ranging from 20 s to 400 s, under conditions which may be present during a loss-of-liquid-coolant accident at a light water nuclear reactor comprises (a) a perforate catalytically active substrate, such as a platinum coated ceramic honeycomb or wire mesh screen, through which heated gases produced by oxidation of the mixture can freely flow and (b) a plurality of thin platinum wires mounted in a thermally conductive manner on the substrate and positioned thereon so as to be able to receive heat from the substrate and the heated gases while also in contact with unoxidized gases.

McLean, William J. (Oakland, CA); Thorne, Lawrence R. (Livermore, CA); Volponi, Joanne V. (Livermore, CA)

1988-01-01T23:59:59.000Z

358

Investigation of ignition of thermoplastics through the Hot Wire Ignition Test  

E-Print Network [OSTI]

. . . . , . . . . , . Ignition Temperature Ranges of PMMA, PE, Nylon and PC ' . . . Plot of Temperature Measurements for Plexiglas 1/16". . . . . . . . . . . . . Plot of Temperature Measurements for Plexiglas 1/8". . . . . . . . . . . . . . . Plot of Temperature Measurements... and Quintiere Materials PMMA Nylon Polyethylene Polypropylene Description Polycast, black, polymethylmeth acr ylate, 2. 5 cm Polypenco, extruded, unfilled, type 6/6, 2. 5 cm Allied Resinous products, Inc. , type tO', 2. 5 cm Poly-Hi, clear, high...

De Araujo, Luiz Claudio Bonilla

1998-01-01T23:59:59.000Z

359

Catalytic ignition of fuel/oxygen/nitrogen mixtures over platinum  

SciTech Connect (OSTI)

Ignition of fuel/oxygen/nitrogen mixtures over platinum wire is experimentally studied by using microcalorimetry and by restricting the flow to the low Reynolds number range so that axisymmetry prevails. The fuels studied are propane, butane, propylene, ethylene, carbon monoxide, and hydrogen. Parameters investigated include flow velocity, fuel type and concentration, and oxygen concentration. The catalytic ignition temperatures of the various fuels are accurately determined over extensive ranges of fuel/oxygen/nitrogen concentrations. Results show two distinctly opposite ignition trends depending on the nature of the fuel. That is, the ignition temperature of lean propane/air and butane/air mixtures decreases as their fuel concentration is increased, while the reverse trend is observed for lean mixtures of propylene, ethylene, carbon monoxide, and hydrogen with air. Furthermore, the ignition of propane depends primarily on fuel concentration, while the ignition of carbon monoxide depends on fuel and oxygen concentrations to a comparable extent. These results are explained on the basis of hierarchical surface adsorption strengths of the different reactants in effecting catalytic ignition. Additional phenomena of interest are observed and discussed.

Cho, P.; Law, C.K.

1986-11-01T23:59:59.000Z

360

Pre-ignition laser ablation of nanocomposite energetic materials  

SciTech Connect (OSTI)

Laser ignition of energetic material composites was studied for initiation with heating rates from 9.5 Multiplication-Sign 10{sup 4} to 1.7 Multiplication-Sign 10{sup 7} K/s. This is a unique heating rate regime for laser ignition studies because most studies employ either continuous wave CO{sub 2} lasers to provide thermal ignition or pulsed Nd:YAG lasers to provide shock ignition. In this study, aluminum (Al) and molybdenum trioxide (MoO{sub 3}) nanoparticle powders were pressed into consolidated pellets and ignited using a Nd:YAG laser (1064 nm wavelength) with varied pulse energy. Results show reduced ignition delay times corresponding to laser powers at the ablation threshold for the sample. Heating rate and absorption coefficient were determined from an axisymmetric heat transfer model. The model estimates absorption coefficients from 0.1 to 0.15 for consolidated pellets of Al + MoO{sub 3} at 1064 nm wavelength. Ablation resulted from fracturing caused by a rapid increase in thermal stress and slowed ignition of the pellet.

Stacy, S. C.; Massad, R. A.; Pantoya, M. L. [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)] [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

EFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA Jianbang Liu1,2  

E-Print Network [OSTI]

to electrical energy consumed to produce the discharge.) Consequently, ignition by laser sources has beenEFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA DISCHARGES Jianbang Liu1,2 , Fei Wang1 with air ignited by transient plasma discharge were investigated and compared with spark discharge ignition

362

Laser ignition of dust clouds INERIS, BP. 2, F-60550 Vemeuil-en-Halatte  

E-Print Network [OSTI]

Laser ignition of dust clouds Ch. PROUST INERIS, BP. 2, F-60550 Vemeuil-en-Halatte ineris-00961863.1051/jp4:20020269 #12;Abstract. In a previous paper [1], the possibility of igniting a combustible dust the scope of the investigated ignition phenomena. In particular a relationship between the standard ignition

Paris-Sud XI, Université de

363

Status Of The National Ignition Campaign And National Ignition Facility Integrated Computer Control System  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that will contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn. NIF is operated by the Integrated Computer Control System (ICCS) in an object-oriented, CORBA-based system distributed among over 1800 frontend processors, embedded controllers and supervisory servers. In the fall of 2010, a set of experiments began with deuterium and tritium filled targets as part of the National Ignition Campaign (NIC). At present, all 192 laser beams routinely fire to target chamber center to conduct fusion and high energy density experiments. During the past year, the control system was expanded to include automation of cryogenic target system and over 20 diagnostic systems to support fusion experiments were deployed and utilized in experiments in the past year. This talk discusses the current status of the NIC and the plan for controls and information systems to support these experiments on the path to ignition.

Lagin, L; Brunton, G; Carey, R; Demaret, R; Fisher, J; Fishler, B; Ludwigsen, P; Marshall, C; Reed, R; Shelton, R; Townsend, S

2011-03-18T23:59:59.000Z

364

On the mechanism of aluminum ignition in steam explosions  

Science Journals Connector (OSTI)

An available theory [Epstein, M., Fauske, H.K., 1994. A crystallization theory of underwater aluminum ignition. Nucl. Eng. Des. 146, 147–164] of the ignition of aluminum melt drops under water, which is based on the assumption that the aluminum oxide (Al2O3) drop-surface skin first appears in a metastable molten state, is compared with existing experimental data on the ignition of aluminum drops behind shock waves in water [Theofanous, T.G., Chen, X., DiPiazza, P., Epstein, M., Fauske, H.K., 1994. Ignition of aluminum droplets behind shock waves in water, Phys. Fluids 6, 3513–3515]. The predicted and measured ignition temperature of about 1770 K coincides approximately with the spontaneous nucleation temperature of supercooled liquid Al2O3 (1760 K). This suggests that the crystallization of the oxide layer represents a strong ‘barrier’ to aluminum drop ignition under water. Apparently a similar interpretation is applicable to aluminum drop ignition in gaseous oxidizing atmospheres. We conclude from the theory that the low-temperature aluminum ignitions (in the range 1100–1600 K) that have been observed during steam explosions are a consequence of the short aluminum drop oxidation times in this environment relative to the characteristic time for Al2O3 crystallization. Several aspects of the aluminum drop/shock interaction experiments besides ignition are discussed in the paper. In particular, the experiments provide strong evidence that during the course of a vapor explosion metal fragmentation occurs via a thermal mechanism at low pressure and precedes the development of a high-pressure shock.

M Epstein; H.K Fauske; T.G Theofanous

2000-01-01T23:59:59.000Z

365

Director of the National Ignition Facility, Lawrence Livermore National  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Director of the National Ignition Facility, Lawrence Livermore National Director of the National Ignition Facility, Lawrence Livermore National Laboratory | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Who We Are > In The Spotlight > Edward Moses Director of the National Ignition Facility, Lawrence Livermore National Laboratory

366

The National Ignition Facility: The Path to Ignition, High Energy Density Science and Inertial Fusion Energy  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is a Nd:Glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light. This world's most energetic laser system is now operational with the goals of achieving thermonuclear burn in the laboratory and exploring the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in the interiors of planetary and stellar environments. On September 29, 2010, NIF performed the first integrated ignition experiment which demonstrated the successful coordination of the laser, the cryogenic target system, the array of diagnostics and the infrastructure required for ignition. Many more experiments have been completed since. In light of this strong progress, the U.S. and the international communities are examining the implication of achieving ignition on NIF for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a 10% electrical-optical efficiency laser, as well as further advances in large-scale target fabrication, target injection and tracking, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in 10- to 15-years. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Energy (LIFE) baseline design and examining various technology choices for LIFE power plant This paper will describe the unprecedented experimental capabilities of the NIF, the results achieved so far on the path toward ignition, the start of fundamental science experiments and plans to transition NIF to an international user facility providing access to researchers around the world. The paper will conclude with a discussion of LIFE, its development path and potential to enable a carbon-free clean energy future.

Moses, E

2011-03-25T23:59:59.000Z

367

Control System For Cryogenic THD Layering At The National Ignition Facility  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 {micro}m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.

Fedorov, M; Blubaugh, J; Edwards, O; Mauvais, M; Sanchez, R; Wilson, B

2011-03-18T23:59:59.000Z

368

HD Applications of Significantly Downsized SI Engines Using Alcohol DI for Knock Avoidance  

Broader source: Energy.gov [DOE]

Direct injection of a second fuel (ethanol or methanol) is explored as a means of avoiding knock in turbocharged, high-compression ratio spark-ignited engines that could replace diesels in certain vocational applications.

369

Reduction of Fuel Consumption By Thermodynamical Optimization of the Otto-Engine  

Science Journals Connector (OSTI)

By the example of the PORSCHE 924 2-liter Otto engine it was demonstrated that the optimization of ... the compression ratio, combustion chamber shape, air/fuel ratio, and ignition timing is a means to reduce fuel

Dr. D. Gruden; R. Hahn; H. Lörcher

1980-01-01T23:59:59.000Z

370

Effect of fuel injection strategies on the combustion process in a PFI boosted SI engine  

Science Journals Connector (OSTI)

A low-cost solution based on fuel injection strategies was investigated to optimize the combustion process in a boosted port fuel injection spark ignition (PFI SI) engine. The goal was to reduce the fuel consumption

S. S. Merola; P. Sementa; C. Tornatore…

2009-10-01T23:59:59.000Z

371

Innovative coal-fueled diesel engine injector. Final report  

SciTech Connect (OSTI)

The purpose of this research investigation was to develop an electronic coal water slurry injection system in conjunction with the Thermal Ignition Combustion System (TICS) concept to achieve autoignition of CWS at various engine load and speed conditions without external ignition sources. The combination of the new injection system and the TICS is designed to reduce injector nozzle spray orifice wear by lowering the peak injection pressure requirements. (VC)

Badgley, P.; Doup, D.

1991-05-01T23:59:59.000Z

372

Frictionally induced ignition processes in drop and skid tests  

SciTech Connect (OSTI)

The standard LANL/Pantex drop and skid tests rely on subjective assessment of reaction violence to quantify the response of the charge, and completely miss nonpropagating hot-spot ignition sites. Additionally, large variations in test results have been observed, which we propose is due to a misunderstanding of the basic physical processes that lead to threshold ignition in these tests. The tests have been redesigned to provide control of these mechanisms and to permit direct observation of hot spots at the impact site, allowing us to follow the progression of the outcome as the drop height and ignition source density are varied. The results confirm that frictional interactions between high-melting-point solids are the dominant ignition mechanism, not just at the threshold, but in fact at all realistic drop heights.

Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

373

Ignition of gas mixtures containing natural gas and oxygen  

Science Journals Connector (OSTI)

Gases released during the thermal treatment of a coal-gas suspension exhibit a strong inhibiting effect on the self-ignition of natural gas but have a minor influence on the...

N. M. Rubtsov; B. S. Seplyarskii; G. I. Tsvetkov…

2010-01-01T23:59:59.000Z

374

The National Ignition Facility and Laser Fusion Energy  

Science Journals Connector (OSTI)

This talk provides an update of the NIC on the National Ignition Facility at the Lawrence Livermore National Laboratory and the roadmap to demonstrate laser fusion as a viable source...

Moses, E I

375

National Ignition Facility & Photon Science HOW NIF WORKS  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NIF WORKS beam me up: how niF works In the National Ignition Facility (NIF), 192 laser beams travel a long path, about 1,500 meters, from their birth at the master oscillator-a...

376

Laser ignition of hypersonic air–hydrogen flow  

Science Journals Connector (OSTI)

An experimental investigation of the behaviour of laser-induced ignition in a hypersonic air–hydrogen flow is ... /s. This study is the first comprehensive laser spark study in a hypersonic flow and demonstrates ...

S. Brieschenk; H. Kleine; S. O’Byrne

2013-09-01T23:59:59.000Z

377

Detonation along laser generated micropinch for fast ignition  

E-Print Network [OSTI]

The proposed fast ignition of highly compressed deuterium-tritium (DT) targets by petawatt lasers requires energy of about 100kJ. To lower the power of the laser, it is proposed to accomplish fast ignition with two lasers, one with lower power in the infrared, and a second one with high power in the visible to ultraviolet region. The infrared laser of lower power shall by its radiation pressure drive a large current in a less than solid density plasma placed inside a capillary, while the second high power-shorter wave length-laser shall ignite at one end of the capillary a magnetic field supported thermonuclear detonation wave in a blanket made from solid DT along the outer surface of the capillary. The other end of the capillary, together with its DT blanket, is stuck in the DT target, where following the compression of the target the detonation wave ignites the target.

Winterberg, F

2008-01-01T23:59:59.000Z

378

Laser-Matter Interaction Above the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction above the plasma ignition threshold intensity. The physics of the pulsed laser ablation process at high intensities is very complex since it invo...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

379

Relativistic electron beam transport for fast ignition relevant scenarios  

E-Print Network [OSTI]

A crucial issue surrounding the feasibility of fast ignition, an alternative inertial confinement fusion scheme, is the ability to efficiently couple energy from an incident short-pulse laser to a high-density, pre-compressed ...

Cottrill, Larissa A

2009-01-01T23:59:59.000Z

380

Application of laser ignition on laminar flame front investigation  

Science Journals Connector (OSTI)

The first stages of laser-induced spark ignition were investigated as a function of time....4/air burner. Laser-induced breakdown was achieved by focusing a ... nanosecond pulse from a Q-switched Nd:YAG laser. An...

J.-L. Beduneau; Y. Ikeda

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Fast ignition of fusion targets by laser-driven electrons  

E-Print Network [OSTI]

We present hybrid PIC simulations of fast electron transport and energy deposition in pre-compressed fusion targets, taking full account of collective magnetic effects and the hydrodynamic response of the background plasma. Results on actual ignition of an imploded fast ignition configuration are shown accounting for the increased beam divergence found in recent experiments [J.S. Green et al., Phys. Rev. Lett. 100, 015003 (2008)] and the reduction of the electron kinetic energy due to profile steepening predicted by advanced PIC simulations [B. Chrisman et al. Phys. Plasmas 15, 056309 (2008)]. Target ignition is studied as a function of injected electron energy, distance of cone-tip to dense core, initial divergence and kinetic energy of the relativistic electron beam. We found that beam collimation reduces substantially the ignition energies of the cone-guided fuel configuration assumed here.

Honrubia, J J

2008-01-01T23:59:59.000Z

382

Laser-Matter Interaction Below the Plasma Ignition Threshold Intensity  

Science Journals Connector (OSTI)

In this chapter we present the process of laser-matter interaction below the plasma ignition threshold intensity. When the high power laser radiation characterized by electric field intensities around ...

Mihai Stafe; Aurelian Marcu; Niculae N. Puscas

2014-01-01T23:59:59.000Z

383

Theory of Fast Electron Transport for Fast Ignition  

E-Print Network [OSTI]

Fast Ignition Inertial Confinement Fusion is a variant of inertial fusion in which DT fuel is first compressed to high density and then ignited by a relativistic electron beam generated by a fast (laser pulse, which is usually brought in to the dense plasma via the inclusion of a re-entrant cone. The transport of this beam from the cone apex into the dense fuel is a critical part of this scheme, as it can strongly influence the overall energetics. Here we review progress in the theory and numerical simulation of fast electron transport in the context of Fast Ignition. Important aspects of the basic plasma physics, descriptions of the numerical methods used, a review of ignition-scale simulations, and a survey of schemes for controlling the propagation of fast electrons are included. Considerable progress has taken place in this area, but the development of a robust, high-gain FI `point design' is still an ongoing challenge.

Robinson, A P L; Davies, J R; Gremillet, L; Honrubia, J J; Johzaki, T; Kingham, R J; Sherlock, M; Solodov, A A

2013-01-01T23:59:59.000Z

384

Ignition technique for an in situ oil shale retort  

DOE Patents [OSTI]

A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

Cha, Chang Y. (Golden, CO)

1983-01-01T23:59:59.000Z

385

Exergy analysis of SI engines  

Science Journals Connector (OSTI)

In this study, exergy (availability) analysis of a Spark Ignition (SI) engine has been performed theoretically during compression, combustion and expansion processes of the engine cycle. For this purpose, a thermodynamic-based engine cycle model is developed without considering the geometric features of fluid motion. Through the analysis, the effects of changing some design and operating parameters, such as compression ratio, fuel-air equivalence ratio and spark timing on the variation and destruction of exergy have been investigated. It was obtained that design and operation conditions have considerable effects on the variation of exergy and irreversibilities during investigated parts of the cycle.

Ismet Sezer; Atilla Bilgin

2008-01-01T23:59:59.000Z

386

Target Diagnostics Supports NIF's Path to Ignition  

SciTech Connect (OSTI)

The physics requirements derived from the National Ignition Facility (NIF) experimental campaigns are leading to a wide variety of target diagnostics. Software development for the control and analysis of these diagnostics is included in the NIF Integrated Computer Control System, Diagnostic Control System and Data Visualization. These projects implement the configuration, controls, data analysis and visual representation of most of these diagnostics. To date, over 40 target diagnostics have been developed to support NIF experiments. In 2011 diagnostics were developed or enhanced to measure Ignition performance in a high neutron yield environment. Performance is optimized around four key variables: Adiabat (a) which is the strength and timing of four shocks delivered to the target, Velocity (V) of the imploding target, Mix (M) is the uniformity of the burn, and the Shape (S) of the imploding Deuterium Tritium (DT) hot spot. The diagnostics used to measure each of these parameters is shown in figure 1. Adiabat is measured using the Velocity Interferometer System for Any Reflector (VISAR) diagnostic consisting of three streak cameras. To provide for more accurate adiabat measurements the VISAR streak cameras were enhanced in FY11 with a ten comb fiducial signal controller to allow for post shot correction of the streak camera sweep non-linearity. Mix is measured by the Neutron Time of Flight (NTOF) and Radiochemical Analysis of Gaseous Samples (RAGS) diagnostics. To accommodate high neutron yield shots, NTOF diagnostic controls are being modified to use Mach Zehnder interferometer signals to allow the digitizers to be moved from near the target chamber to the neutron shielded diagnostic mezzanine. In December 2011 the first phase of RAGS diagnostic commissioning will be completed. This diagnostic will analyze the tracers that are added to NIF target capsules that undergo nuclear reactions during the shot. These gases are collected and purified for nuclear counting by the RAGS system. Three new instrument controllers were developed and commissioned to support this diagnostic. A residual-gas analyzer (RGA) instrument measures the gas content at various points in the system. The Digital Gamma Spectrometer instrument measures the radiological spectrum of the decaying gas isotopes. A final instrument controller was developed to interface to a PLC based Gas collection system. In order to support the implosion velocity measurements an additional Gated X-ray Detector (GXD) diagnostic was tested and commissioned. This third GXD views the target through a slit contained in its snout and allows the other GXD diagnostics to be used for measuring the shape on the same shot. In order to measure the implosion shape in a high neutron environment, Actide Readout In A Neutron Environment (ARIANE) and Neutron Imaging (NI) diagnostics were commissioned. The controls for ARIANE, a fixed port gated x-ray imager, contain a neutron shielded camera and micro channel plate pulser with its neutron sensitive electronics located in the diagnostic mezzanine. The NI diagnostic is composed of two Spectral Instruments SI-1000 cameras located 20M from the target and provides neutron images of the DT hot spot for high yield shots. The development and commissioning of these new or enhanced diagnostics in FY11 have provided meaningful insight that facilitates the optimization of the four key Ignition variables. In FY12 they will be adding three new diagnostics and enhancing four existing diagnostics in support of the continuing optimization series of campaigns.

Shelton, R

2011-12-07T23:59:59.000Z

387

Laser Spark Ignition of Premixed Methane-Air Mixtures: Parameter Measurements and Determination of Key Factors for Ultimate Ignition Results  

Science Journals Connector (OSTI)

In this study, we present an experimental investigation of the parameters of the laser spark ignition of premixed methane-air mixtures and the determination of the key factors for the...

Li, Xiaohui; Smith, Benjamin W; Omenetto, Nicoló

2014-01-01T23:59:59.000Z

388

Testing of a Continuous Detonation Wave Engine with Swirled Injection  

E-Print Network [OSTI]

Testing of a Continuous Detonation Wave Engine with Swirled Injection Eric M. Braun Nathan L. Dunn detonation wave engines with swirl to improve mixing were developed. The reactants were ignited with an ordinary automotive spark plug. Mixing and detonation occurred in a common annular chamber in the first

Texas at Arlington, University of

389

Monitoring system assists in dual-fuel engine knock prevention  

SciTech Connect (OSTI)

ABB Industrietechnik AG recently has introduced an augmented version of its Cyldeyt cylinder pressure monitoring system aimed at spark-ignited and diesel/gas, dual-fuel engines. In addition to recording and evaluating cylinder pressure as a means of assessing engine condition, the new Cyldet version now evaluates the cylinder pressure signals to provide protection against pre-ignition related damage. When pre-ignition reaches critical levels, the Cyldet computer relays alarm signals in two stages to the overriding engine control system of the power plant. On receiving the first-stage alarm signal, the engine control system is programmed to adjust one or more engine settings to eliminate preignition - a typical adjustment is to lower charge-air temperature, for example. If such measures fail to eliminate pre-ignition, in the case of a dual-fuel engine, a second alarm signal triggers a reduction in engine load or, as last resort, changeover of the engine to 100% diesel fuel charge. This paper outlines the advantages and applications of the system. 1 fig., 1 tab.

Not Available

1995-03-01T23:59:59.000Z

390

Development of an engine fuel and spark controller  

E-Print Network [OSTI]

The objective of this research was to develop an engine control unit (ECU) for a four cylinder engine to be used in a Formula SAE racers. The ECU must provide effective fuel injection and spark ignition control and provide for easy adjustment...

Suter, William Gregory

2012-06-07T23:59:59.000Z

391

Novel injector techniques for coal-fueled diesel engines  

SciTech Connect (OSTI)

This report, entitled Novel Injector Techniques for Coal-Fueled Diesel Engines,'' describes the progress and findings of a research program aimed at development of a dry coal powder fuel injector in conjunction with the Thermal Ignition Combustion System (TICS) concept to achieve autoignition of dry powdered coal in a single-cylinder high speed diesel engine. The basic program consisted of concept selection, analysis and design, bench testing and single cylinder engine testing. The coal injector concept which was selected was a one moving part dry-coal-powder injector utilizing air blast injection. Adiabatics has had previous experience running high speed diesel engines on both direct injected directed coal-water-slurry (CWS) fuel and also with dry coal powder aspirated into the intake air. The Thermal Ignition Combustion System successfully ignited these fuels at all speeds and loads without requiring auxiliary ignition energy such as pilot diesel fuel, heated intake air or glow or spark plugs. Based upon this prior experience, it was shown that the highest efficiency and fastest combustion was with the dry coal, but that the use of aspiration of coal resulted in excessive coal migration into the engine lubrication system. Based upon a desire of DOE to utilize a more modern test engine, the previous naturally-aspirated Caterpillar model 1Y73 single cylinder engine was replaced with a turbocharged (by use of shop air compressor and back pressure control valve) single cylinder version of the Cummins model 855 engine.

Badgley, P.R.

1992-09-01T23:59:59.000Z

392

Method and system for controlled combustion engines  

DOE Patents [OSTI]

A system for controlling combustion in internal combustion engines of both the Diesel or Otto type, which relies on establishing fluid dynamic conditions and structures wherein fuel and air are entrained, mixed and caused to be ignited in the interior of a multiplicity of eddies, and where these structures are caused to sequentially fill the headspace of the cylinders.

Oppenheim, A. K. (Berkeley, CA)

1990-01-01T23:59:59.000Z

393

Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility  

SciTech Connect (OSTI)

The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8?MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6?×?10{sup 13} and ?0.3?g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2014-05-15T23:59:59.000Z

394

National Ignition Facility Project Site Safety Program  

SciTech Connect (OSTI)

This Safety Program for the National Ignition Facility (NIF) presents safety protocols and requirements that management and workers shall follow to assure a safe and healthful work environment during activities performed on the NIF Project site. The NIF Project Site Safety Program (NPSSP) requires that activities at the NIF Project site be performed in accordance with the ''LLNL ES&H Manual'' and the augmented set of controls and processes described in this NIF Project Site Safety Program. Specifically, this document: (1) Defines the fundamental NIF site safety philosophy. (2) Defines the areas covered by this safety program (see Appendix B). (3) Identifies management roles and responsibilities. (4) Defines core safety management processes. (5) Identifies NIF site-specific safety requirements. This NPSSP sets forth the responsibilities, requirements, rules, policies, and regulations for workers involved in work activities performed on the NIF Project site. Workers are required to implement measures to create a universal awareness that promotes safe practice at the work site and will achieve NIF management objectives in preventing accidents and illnesses. ES&H requirements are consistent with the ''LLNL ES&H Manual''. This NPSSP and implementing procedures (e.g., Management Walkabout, special work procedures, etc.,) are a comprehensive safety program that applies to NIF workers on the NIF Project site. The NIF Project site includes the B581/B681 site and support areas shown in Appendix B.

Dun, C

2003-09-30T23:59:59.000Z

395

The National Ignition Facility and the Path to Fusion Energy  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) is operational and conducting experiments at the Lawrence Livermore National Laboratory (LLNL). The NIF is the world's largest and most energetic laser experimental facility with 192 beams capable of delivering 1.8 megajoules of 500-terawatt ultraviolet laser energy, over 60 times more energy than any previous laser system. The NIF can create temperatures of more than 100 million degrees and pressures more than 100 billion times Earth's atmospheric pressure. These conditions, similar to those at the center of the sun, have never been created in the laboratory and will allow scientists to probe the physics of planetary interiors, supernovae, black holes, and other phenomena. The NIF's laser beams are designed to compress fusion targets to the conditions required for thermonuclear burn, liberating more energy than is required to initiate the fusion reactions. Experiments on the NIF are focusing on demonstrating fusion ignition and burn via inertial confinement fusion (ICF). The ignition program is conducted via the National Ignition Campaign (NIC) - a partnership among LLNL, Los Alamos National Laboratory, Sandia National Laboratories, University of Rochester Laboratory for Laser Energetics, and General Atomics. The NIC program has also established collaborations with the Atomic Weapons Establishment in the United Kingdom, Commissariat a Energie Atomique in France, Massachusetts Institute of Technology, Lawrence Berkeley National Laboratory, and many others. Ignition experiments have begun that form the basis of the overall NIF strategy for achieving ignition. Accomplishing this goal will demonstrate the feasibility of fusion as a source of limitless, clean energy for the future. This paper discusses the current status of the NIC, the experimental steps needed toward achieving ignition and the steps required to demonstrate and enable the delivery of fusion energy as a viable carbon-free energy source.

Moses, E

2011-07-26T23:59:59.000Z

396

A polar-drive-ignition design for the National Ignition Facility  

SciTech Connect (OSTI)

Polar drive [Skupsky et al., Phys. Plasmas 11, 2763 (2004)] will enable direct-drive experiments to be conducted on the National Ignition Facility (NIF) [Miller et al., Opt. Eng. 43, 2841 (2004)], while the facility is configured for x-ray drive. A polar-drive ignition design for the NIF has been developed that achieves a gain of 32 in two-dimensional (2-D) simulations, which include single- and multiple-beam nonuniformities and ice and outer-surface roughness. This design requires both single-beam UV polarization smoothing and one-dimensional (1-D) multi-frequency modulator (MFM) single-beam smoothing to achieve the required laser uniformity. The multi-FM smoothing is employed only during the low-intensity portion of the laser pulse, allowing for the use of sufficient smoothing-by-spectral-dispersion bandwidth while maintaining safe laser operations during the high-intensity part of the pulse. This target is robust to all expected sources of perturbations.

Collins, T. J. B.; Marozas, J. A.; Anderson, K. S.; Craxton, R. S.; Delettrez, J. A.; Goncharov, V. N.; Harding, D. R.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Radha, P. B.; Shvydky, A.; Skupsky, S.; Zuegel, J. D. [Laboratory for Laser Energetics, 250E. River Rd, Rochester, New York 14623 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, 250E. River Rd, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2012-05-15T23:59:59.000Z

397

Controlling the Electrostatic Discharge Ignition Sensitivity of Composite Energetic Materials Using Carbon Nanotube Additives  

SciTech Connect (OSTI)

Powder energetic materials are highly sensitive to electrostatic discharge (ESD) ignition. This study shows that small concentrations of carbon nanotubes (CNT) added to the highly reactive mixture of aluminum and copper oxide (Al + CuO) significantly reduces ESD ignition sensitivity. CNT act as a conduit for electric energy, bypassing energy buildup and desensitizing the mixture to ESD ignition. The lowest CNT concentration needed to desensitize ignition is 3.8 vol.% corresponding to percolation corresponding to an electrical conductivity of 0.04 S/cm. Conversely, added CNT increased Al + CuO thermal ignition sensitivity to a hot wire igniter.

Kade H. Poper; Eric S. Collins; Michelle L. Pantoya; Michael Daniels

2014-10-01T23:59:59.000Z

398

Towards model-based control of a steam Rankine process for engine waste heat recovery  

E-Print Network [OSTI]

Towards model-based control of a steam Rankine process for engine waste heat recovery Johan Peralez steam process for exhaust gas heat recovery from a spark-ignition engine, focusing in particular results on a steam process for SI engines, [3] on generic control issues and [4] which provides a comp

Paris-Sud XI, Université de

399

Evaluating the ignition sensitivity of thermal battery heat pellets  

SciTech Connect (OSTI)

Thermal batteries are activated by the ignition of heat pellets. If the heat pellets are not sensitive enough to the ignition stimulus, the thermal battery will not activate, resulting in a dud. Thus, to assure reliable thermal batteries, it is important to demonstrate that the pellets have satisfactory ignition sensitivity by testing a number of specimens. There are a number of statistical methods for evaluating the sensitivity of a device to some stimulus. Generally, these methods are applicable to the situation in which a single test is destructive to the specimen being tested, independent of the outcome of the test. In the case of thermal battery heat pellets, however, tests that result in a nonresponse do not totally degrade the specimen. This peculiarity provides opportunities to efficiently evaluate the ignition sensitivity of heat pellets. In this paper, a simple strategy for evaluating heat pellet ignition sensitivity (including experimental design and data analysis) is described. The relatively good asymptotic and small-sample efficiencies of this strategy are demonstrated.

Thomas, E.V.

1993-09-01T23:59:59.000Z

400

THE AUTOIGNITION OF CYCLOPENTANE IN AN IGNITION QUALITY TESTER  

SciTech Connect (OSTI)

Cyclopentane, a flammable hydrocarbon, is being considered as a working fluid for waste heat recovery applications using Organic Rankine Cycles with Direct Evaporators. A postulated failure mode consisting of a pinhole leak in a heat exchanger tube raises safety concerns due to autoignition of the working fluid. The ignition delay time (IDT) of cyclopentane was measured using an Ignition Quality Test™ (IQT™) device. Hot, vitiated air was used to simulate turbine exhaust gas (TEG). Experiments were conducted in accordance with ASTM D6890 (with exception to charge pressure and temperature) to determine ignition delay of the fuel at atmospheric pressure for vitiated air (13.3% oxygen). The test matrixencompassed equivalence ratios from 0.5 to 5.0 and chamber temperatures ranging from 673 to 823 K to establish a set of ignition delay curves. IDT was observed to decrease with increasing temperature and equivalence ratio. For the cases tested, no ignition was observed at temperatures at or below 723 K or at an equivalence ratio of 0.5.

Donna Post Guillen

2012-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Symmetry tuning for ignition capsules via the symcap technique  

SciTech Connect (OSTI)

Symmetry of an implosion is crucial to get ignition successfully. Several methods of control and measurement of symmetry have been applied on many laser systems with mm size hohlraums and ns pulses. On the National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] we have large hohlraums of cm scale, long drive pulses of 10 s of ns, and a large number of beams with the option to tune their wavelengths. Here we discuss how we used the x-ray self-emission from imploding surrogates to ignition capsules (symcaps) to measure the symmetry of the implosion. We show that symcaps are good surrogates for low order symmetry, though having lower sensitivity to distortions than ignition capsules. We demonstrate the ability to transfer energy between laser beams in a gas-filled hohlraum using wavelength tuning, successfully tuning the lowest order symmetry of the symcaps in different size hohlraums at different laser energies within the specification established by calculations for successful ignition.

Kyrala, G. A.; Kline, J. L. [Los Alamos National Laboratory, P.O. Box 1663, MS E-526, Los Alamos, New Mexico 87544 (United States); Dixit, S.; Glenzer, S.; Kalantar, D.; Bradley, D.; Izumi, N.; Meezan, N.; Landen, O.; Callahan, D.; Weber, S. V.; Holder, J. P.; Glenn, S.; Edwards, M. J.; Koch, J.; Suter, L. J.; Haan, S. W.; Town, R. P. J.; Michel, P.; Jones, O. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2011-05-15T23:59:59.000Z

402

AN ENGINEERING TEST FACILITY FOR HEAVY ION FUSION OPTIONS AND SCALING W.R. Meier, D.A. Callahan-Miller, J.F. Latkowski,  

E-Print Network [OSTI]

.A. Callahan-Miller, J.F. Latkowski, B.G. Logan, J.D. Lindl Lawrence Livermore National Laboratory P.O. Box 808 Livermore, California 94551 (925) 422-8536 P.F. Peterson Department of Nuclear Engineering University will be the demonstration of indirect-drive ignition and gain on the National Ignition Facility (NIF), to confirm capsule

403

Engineering Electrical &  

E-Print Network [OSTI]

Computer Engineering Electrical & Electronic Engineering Mechatronics Engineering Mechanical Engineering Civil Engineering Natural Resources Engineering Forest Engineering Chemical & Process Engineering ELECTIVE 2 Required Engineering Intermediate Year 2012 Eight Required Courses Chart: 120 points College

Hickman, Mark

404

Engineering Electrical &  

E-Print Network [OSTI]

Computer Engineering Electrical & Electronic Engineering Mechatronics Engineering Mechanical Engineering Civil Engineering Natural Resources Engineering Forest Engineering Chemical & Process Engineering ELECTIVE 2 Required Engineering Intermediate Year 2011 Eight Required Courses Chart: 120 points College

Hickman, Mark

405

Effectiveness of Diesel Oxidation Catalyst in Reducing HC and CO Emissions from Reactivity Controlled Compression Ignition  

SciTech Connect (OSTI)

Reactivity Controlled Compression Ignition (RCCI) has been shown to allow for diesel-like or better brake thermal efficiency with significant reductions in nitrogen oxide (NOX) particulate matter (PM) emissions. Hydrocarbon (HC) and carbon monoxide (CO) emission levels, on the other hand, are similar to those of port fuel injected gasoline engines. The higher HC and CO emissions combined with the lower exhaust temperatures with RCCI operation present a challenge for current exhaust aftertreatments. The reduction of HC and CO emissions in a lean environment is typically achieved with an oxidation catalyst. In this work, several diesel oxidation catalysts (DOC) with different precious metal loadings were evaluated for effectiveness to control HC and CO emissions from RCCI combustion in a light-duty multi-cylinder engine operating on gasoline and diesel fuels. Each catalyst was evaluated in a steady-state engine operation with temperatures ranging from 160 to 260 C. A shift to a higher light-off temperature was observed during the RCCI operation. In addition to the steady-state experiments, the performances of the DOCs were evaluated during multi-mode engine operation by switching from diesel-like combustion at higher exhaust temperature and low HC/CO emissions to RCCI combustion at lower temperature and higher HC/CO emissions. High CO and HC emissions from RCCI generated an exotherm keeping the catalyst above the light-off temperature.

Prikhodko, Vitaly Y [ORNL; Curran, Scott [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL

2013-01-01T23:59:59.000Z

406

Ignition characteristics of methane/air premixed mixture by microwave-enhanced laser-induced breakdown plasma  

Science Journals Connector (OSTI)

A microwave-enhanced plasma generation technique was combined with laser-induced ignition to improve ignition characteristics. A locally intensified microwave field was formed near the...

Nishiyama, Atsushi; Moon, Ahsa; Ikeda, Yuji; Hayashi, Jun; Akamatsu, Fumiteru

2013-01-01T23:59:59.000Z

407

Planetary and Protostellar Nuclear Fission: Implications for Planetary Change, Stellar Ignition and Dark Matter  

Science Journals Connector (OSTI)

...changes in the geomagnetic field. The concept that thermonuclear fusion reactions in stars are ignited by nuclear fission...protostellar nuclear fission reactors failed to ignite thermonuclear fusion reactions. The Royal Society is collaborating...

1994-01-01T23:59:59.000Z

408

Laser induced spark ignition of coaxial methane/oxygen/nitrogen diffusion flames  

Science Journals Connector (OSTI)

We report the laser induced spark ignition (LSI) of coaxial methane/oxygen/nitrogen diffusion flames using the 1064 nm output of a Q-switched Nd:YAG laser. The minimum ignition energy...

Li, Xiaohui; Yu, Yang; Yu, Xin; Liu, Chang; Fan, Rongwei; Chen, Deying

2014-01-01T23:59:59.000Z

409

Laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target  

Science Journals Connector (OSTI)

We report the laser ablation ignition of premixed methane and oxygen-enriched air mixtures using a tantalum target. The minimum laser pulse energy (MPE) of the ablation ignition was...

Li, Xiaohui; Yu, Xin; Fan, Rongwei; Yu, Yang; Liu, Chang; Chen, Deying

2014-01-01T23:59:59.000Z

410

Ignition of a combustible gas mixture by a laser spark excited in the reactor volume  

Science Journals Connector (OSTI)

Ignition of a stoichiometric CH4: O2 mixture by a laser spark excited in the reactor volume is ... which indicates fast (involving branching chain reactions) ignition of the gas mixture. A conclusion is ... regar...

S. Yu. Kazantsev; I. G. Kononov; I. A. Kossyi; N. M. Tarasova…

2009-03-01T23:59:59.000Z

411

The National Ignition Facility: A New Era in High Energy Density Science  

SciTech Connect (OSTI)

The National Ignition Facility, the world's most energetic laser system, is now operational. This talk will describe NIF, the ignition campaign, and new opportunities in fusion energy and high energy density science enabled by NIF.

Moses, E

2009-06-10T23:59:59.000Z

412

Laser ignition of flammable mixtures via a solid core optical fiber  

Science Journals Connector (OSTI)

To date no commercial fiber coupled laser systems have reached the irradiance and pulse energy required for flammable mixtures ignition. In this work we report preliminary results on the ignition of two-phase mix...

H. El-Rabii; G. Gaborel

2007-03-01T23:59:59.000Z

413

Past experiences with automotive external combustion engines  

SciTech Connect (OSTI)

GMR (General Motors Research Laboratories, now GM R and D Center) has a history of improving the internal combustion engine, especially as it relates to automotive use. During the quarter century from 1950--75, considerable effort was devoted to evaluating alternative powerplants based on thermodynamic cycles different from those on which the established spark-ignition and diesel engines are founded. Two of these, the steam engine and the Stirling engine, incorporated external combustion. Research on those two alternatives is reviewed. Both were judged to fall short of current needs for commercial success as prime movers for conventional automotive vehicles.

Amann, C.A.

1999-07-01T23:59:59.000Z

414

Diagnosing and controlling mix in National Ignition Facility implosion experiments  

SciTech Connect (OSTI)

High mode number instability growth of ''isolated defects'' on the surfaces of National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] capsules can be large enough for the perturbation to penetrate the imploding shell, and produce a jet of ablator material that enters the hot-spot. Since internal regions of the CH ablator are doped with Ge, mixing of this material into the hot-spot results in a clear signature of Ge K-shell emission. Evidence of jets entering the hot-spot has been recorded in x-ray images and spectra, consistent with simulation predictions [Hammel et al., High Energy Density Phys. 6, 171 (2010)]. Ignition targets have been designed to minimize instability growth, and capsule fabrication improvements are underway to reduce ''isolated defects.'' An experimental strategy has been developed where the final requirements for ignition targets can be adjusted through direct measurements of mix and experimental tuning.

Hammel, B. A.; Scott, H. A.; Cerjan, C.; Clark, D. S.; Edwards, M. J.; Glenzer, S. H.; Haan, S. W.; Izumi, N.; Koch, J. A.; Landen, O. L.; Langer, S. H.; Smalyuk, V. A.; Suter, L. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Regan, S. P.; Epstein, R. [University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Kyrala, G. A.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Peterson, K. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2011-05-15T23:59:59.000Z

415

WILDFIRE IGNITION RESISTANCE ESTIMATOR WIZARD SOFTWARE DEVELOPMENT REPORT  

SciTech Connect (OSTI)

This report describes the development of a software tool, entitled “WildFire Ignition Resistance Estimator Wizard” (WildFIRE Wizard, Version 2.10). This software was developed within the Wildfire Ignition Resistant Home Design (WIRHD) program, sponsored by the U. S. Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection & Disaster Management Division. WildFIRE Wizard is a tool that enables homeowners to take preventive actions that will reduce their home’s vulnerability to wildfire ignition sources (i.e., embers, radiant heat, and direct flame impingement) well in advance of a wildfire event. This report describes the development of the software, its operation, its technical basis and calculations, and steps taken to verify its performance.

Phillips, M.; Robinson, C.; Gupta, N.; Werth, D.

2012-10-10T23:59:59.000Z

416

Ignition Delay Times of Kerosene(Jet-A)/Air Mixtures  

E-Print Network [OSTI]

Ignition of Jet-A/air mixtures was studied behind reflected shock waves. Heating of shock tube at temperature of 150 C was used to prepare a homogeneous fuel mixture. Ignition delay times were measured from OH emission at 309 nm and from absorption of He-Ne laser radiation at 3.3922 micrometers. The conditions behind shock waves were calculated by one-dimensional shock wave theory from initial conditions T1, P1, mixture composition and incident shock wave velocity. The ignition delay times were obtained at two fixed pressures 10, 20 atm for lean, stoichiometric and rich mixtures (ER=0.5, 1, 2) at an overall temperature range of 1040-1380 K.

Zhukov, V P; Starikovskii, A Yu

2012-01-01T23:59:59.000Z

417

Shock timing on the National Ignition Facility: First Experiments  

SciTech Connect (OSTI)

An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

Celliers, P M; Robey, H F; Boehly, T R; Alger, E; Azevedo, S; Berzins, L V; Bhandarkar, S D; Bowers, M W; Brereton, S J; Callahan, D; Castro, C; Chandrasekaran, H; Choate, C; Clark, D; Coffee, K R; Datte, P S; Dewald, E L; DiNicola, P; Dixit, S; Doeppner, T; Dzenitis, E; Edwards, M J; Eggert, J H; Fair, J; Farley, D R; Frieders, G; Gibson, C R; Giraldez, E; Haan, S; Haid, B; Hamza, A V; Haynam, C; Hicks, D G; Holunga, D M; Horner, J B; Jancaitis, K; Jones, O S; Kalantar, D; Kline, J L; Krauter, K G; Kroll, J J; LaFortune, K N; Pape, S L; Malsbury, T; Maypoles, E R; Milovich, J L; Moody, J D; Moreno, K; Munro, D H; Nikroo, A; Olson, R E; Parham, T; Pollaine, S; Radousky, H B; Ross, G F; Sater, J; Schneider, M B; Shaw, M; Smith, R F; Thomas, C A; Throop, A; Town, R J; Trummer, D; Van Wonterghem, B M; Walters, C F; Widmann, K; Widmayer, C; Young, B K; Atherton, L J; Collins, G W; Landen, O L; Lindl, J D; MacGowan, B J; Meyerhofer, D D; Moses, E I

2011-10-24T23:59:59.000Z

418

Ion beam requirements for fast ignition of inertial fusion targets  

E-Print Network [OSTI]

Ion beam requirements for fast ignition are investigated by numerical simulation taking into account new effects such as ion beam divergence not included before. We assume that ions are generated by the TNSA scheme in a curved foil placed inside a re-entrant cone and focused on the cone apex or beyond. From the focusing point to the compressed core ions propagate with a given divergence angle. Ignition energies are obtained for two compressed fuel configurations heated by proton and carbon ion beams. The dependence of the ignition energies on the beam divergence angle and on the position of the ion beam focusing point have been analysed. Comparison between TNSA and quasi-monoenergetic ions is also shown.

Honrubia, J J

2015-01-01T23:59:59.000Z

419

A cycle simulation of coal particle fueled reciprocating internal-combustion engines  

E-Print Network [OSTI]

- Summary of Experimental Diesel Engine Operation on Solid Coal Fuels Page Table 2 - Property Data for Coal (Char) Particles . . 23 Table 3 - Summary of the Combustion Model and Reaction Constants 40 Table 4 ? Specifications of the Base Case Engine... Efforts The first attempt to operate a solid particle fueled piston engine was performed nearly a century ago by Rudolf Diesel, inventor of the compression-ignition engine. Since then, at least a dozen separate attempts to oper- ate diesel engines...

Rosegay, Kenneth Harold

2012-06-07T23:59:59.000Z

420

AIAA 010189 Ignition and Flame Studies for  

E-Print Network [OSTI]

technological improvement. The gas turbine engine is not the only potential application for this tech- nology in fuel consumption by intentionally burning fuel in the turbine stages. For the ground-based gas turbine, CA 92697-3975 A computational method is developed for solving the full compressible Navier

Liu, Feng

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

A TUTORIAL ON IGNITION AND GAIN FOR SMALL FUSION TARGETS  

SciTech Connect (OSTI)

Nuclear fusion was discovered experimentally in 1933-34 and other charged particle nuclear reactions were documented shortly thereafter. Work in earnest on the fusion ignition problem began with Edward Teller's group at Los Alamos during the war years. His group quantified all the important basic atomic and nuclear processes and summarized their interactions. A few years later, the success of the early theory developed at Los Alamos led to very successful thermonuclear weapons, but also to decades of unsuccessful attempts to harness fusion as an energy source of the future. The reasons for this history are many, but it seems appropriate to review some of the basics with the objective of identifying what is essential for success and what is not. This tutorial discusses only the conditions required for ignition in small fusion targets and how the target design impacts driver requirements. Generally speaking, the driver must meet the energy, power and power density requirements needed by the fusion target. The most relevant parameters for ignition of the fusion fuel are the minimum temperature and areal density (rhoR), but these parameters set secondary conditions that must be achieved, namely an implosion velocity, target size and pressure, which are interrelated. Despite the apparent simplicity of inertial fusion targets, there is not a single mode of fusion ignition, and the necessary combination of minimum temperature and areal density depends on the mode of ignition. However, by providing a magnetic field of sufficient strength, the conditions needed for fusion ignition can be drastically altered. Magnetized target fusion potentially opens up a vast parameter space between the extremes of magnetic and inertial fusion.

Kirkpatrick, R. C. [Los Alamos National Laboratory, Los Alamos, NM 087545 (United States)

2009-07-26T23:59:59.000Z

422

Engineering Engineering Education  

E-Print Network [OSTI]

E School of Engineering Engineering Education in a University Setting 292 Degree Programs in Engineering 294 Special Programs 296 Honors 298 Academic Regulations 300 Courses of Study 305 Engineering of Engineering is the largest and oldest private engineering school in the South. Classes offering engineering

Simaan, Nabil

423

Ignition and combustion drive by powerful laser radiation acting on a water surface  

Science Journals Connector (OSTI)

The ignition and combustion effects in water vapor generated...2-laser radiation on a water surface are investigated...

G. I. Kozlov; V. A. Kuznetsov

424

Features of a point design for fast ignition  

SciTech Connect (OSTI)

Fast Ignition is an inertial fusion scheme in which fuel is first assembled and then heated to the ignition temperature with an external heating source. In this note we consider cone and shell implosions where the energy supplied by short pulse lasers is transported to the fuel by electrons. We describe possible failure modes for this scheme and how to overcome them. In particular, we describe two sources of cone tip failure, an axis jet driven from the compressed fuel mass and hard photon preheat leaking through the implosion shell, and laser prepulse that can change the position of laser absorption and the angular distribution of the emitted electrons.

Tabak, M; Clark, D; Town, R J; Key, M H; Amendt, P; Ho, D; Meeker, D J; Shay, H D; Lasinski, B F; Kemp, A; Divol, L; Mackinnon, A J; Patel, P; Strozzi, D; Grote, D P

2009-10-26T23:59:59.000Z

425

Progress toward Ignition with Noncryogenic Double-Shell Capsules  

SciTech Connect (OSTI)

Inertial confinement fusion implosions using capsules with two concentric shells separated by a low density region (double shells) are reported which closely follow one dimensional (1D) radiatively driven hydrodynamics simulations. Capsule designs which mitigate Au M -band radiation asymmetries appear to correspond more closely to 1D simulations than targets lacking mitigation of hohlraum drive M -band nonuniformities. One capsule design achieves over 50% of the unperturbed 1D calculated yield at a convergence ratio of 25.5, comparable to that of a double-shell design for an ignition capsule at the National Ignition Facility. (c) 2000 The American Physical Society.

Varnum, W. S.; Delamater, N. D.; Evans, S. C.; Gobby, P. L.; Moore, J. E.; Wallace, J. M.; Watt, R. G.; Colvin, J. D.; Turner, R.; Glebov, V. (and others) [and others

2000-05-29T23:59:59.000Z

426

High Performance Imaging Streak Camera for the National Ignition Facility  

SciTech Connect (OSTI)

An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high EMI. A train of temporal UV timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented.

Opachich, Y. P. [LLNL; Kalantar, D. [LLNL; MacPhee, A. [LLNL; Holder, J. [LLNL; Kimbrough, J. [LLNL; Bell, P. M. [LLNL; Bradley, D. [LLNL; Hatch, B. [LLNL; Brown, C. [LLNL; Landen, O. [LLNL; Perfect, B. H. [LLNL, HMC; Guidry, B. [LLNL; Mead, A. [NSTec; Charest, M. [NSTec; Palmer, N. [LLNL; Homoelle, D. [LLNL; Browning, D. [LLNL; Silbernagel, C. [NSTec; Brienza-Larsen, G. [NSTec; Griffin, M. [NSTec; Lee, J. J. [NSTec; Haugh, M. J. [NSTec

2012-12-01T23:59:59.000Z

427

Ignition feedback regenerative free electron laser (FEL) amplifier  

DOE Patents [OSTI]

An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.

Kim, Kwang-Je (Burr Ridge, IL); Zholents, Alexander (Walnut Creek, CA); Zolotorev, Max (Oakland, CA)

2001-01-01T23:59:59.000Z

428

ICDERS July 2429, 2011 Irvine, USA An Empirical Model for the Ignition of Aluminum Particle  

E-Print Network [OSTI]

23rd ICDERS July 24­29, 2011 Irvine, USA An Empirical Model for the Ignition of Aluminum Particle of aluminum particle clouds is developed and applied to the study of particle ignition and combustion behavior as cloud concentration effects on ignition. The total mass of aluminum that burns is found to depend

429

Time-dependent laser ignition of a combustible stagnant boundary layer  

Science Journals Connector (OSTI)

......research-article Articles Time-dependent laser ignition of a combustible stagnant boundary...55,257-268 Time-dependent laser ignition of a combustible stagnant boundary...examines the conditions for laser ignition of a number of industrial gases......

J. ADLER

1995-12-01T23:59:59.000Z

430

Initial experiments on the shock-ignition inertial confinement fusion concepta...  

E-Print Network [OSTI]

ignition is a concept for direct-drive laser inertial confinement fusion ICF Refs. 1­3 that was recently for conven- tional ignition to occur. Then a strong shock wave launched at the end of the laser pulseInitial experiments on the shock-ignition inertial confinement fusion concepta... W. Theobald,1,b R

431

Plasma channel from EP beam Direct-drive ignition is the main thrust in LLE  

E-Print Network [OSTI]

ignition and radiography I2094 The OMEGA laser at the University of Rochester's Laboratory for LaserPlasma channel from EP beam #12;Direct-drive ignition is the main thrust in LLE fusion research activities I2092 · FusionresearchatLLEisfocusedonbuildingthefoundations for a direct-drive­ignition

432

Capsule implosion optimization during the indirect-drive National Ignition Campaign  

E-Print Network [OSTI]

and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement. INTRODUCTION A. Indirect-drive design The National Ignition Facility (NIF)1 is a 192 beam, 1.8 MJ 0.35 lm laserCapsule implosion optimization during the indirect-drive National Ignition Campaign O. L. Landen,1

433

Large Eddy Simulation of spark ignition in a turbulent methane jet  

E-Print Network [OSTI]

and propagation and (4) stabilization. In the context of laser and electrical spark ignition (which is the scope applications of laser ignition and comparison with standard spark plug devices. Phuoc et al. [5] presentLarge Eddy Simulation of spark ignition in a turbulent methane jet G. Lacaze a , E. Richardson b

Paris-Sud XI, Université de

434

A metamodeling approach for studying ignition target robustness in a highly dimensional parameter space  

E-Print Network [OSTI]

-up, kinetic energy ignition margin, laser-plasma instabilities, etc. As there are several design parametersA metamodeling approach for studying ignition target robustness in a highly dimensional parameter designed to ignite their central hot spots and burn. Changes in the optimal implosion could reduce

Garnier, Josselin

435

Use of a Thermodynamic Engine Cycle Simulation to Study a Turbocharged Spark-ignition Engine  

E-Print Network [OSTI]

indicated that turbocharger does not add considerably to the overall irreversibilities and combustion irreversibility is still the major source of exergy destruction. A comprehensive parametric investigation was also performed to investigate the effects...

Lawand, Vaibhav

2010-07-14T23:59:59.000Z

436

High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines  

Broader source: Energy.gov [DOE]

Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008 in Bethesda, Maryland.

437

Implementation of Engine Control and Measurement Strategies for Biofuel Research in Compression-Ignition Engines  

E-Print Network [OSTI]

) in M2SEC Basement. ___________________ 353 Figure 5-41. 480VAC Transformer (left) and Dynamometer Drive Cabinet (right). ________________ 353 Figure 5-42. Dynamometer Power Lockout Cabinet Closed (left) and Open (right). _______________ 354 Figure 5...-43. Disconnect Switch in Dynamometer Lockout Cabinet. ___________________________ 355 Figure 5-44. Dynamometer Junction Box Internal Connections. ______________________________ 355 Figure 5-45. Dynamometer Control and Monitoring Interface...

Mangus, Michael D.

2014-05-31T23:59:59.000Z

438

Dimethyl Ether Autoignition at Engine-Relevant Conditions  

Science Journals Connector (OSTI)

† Key Laboratory for Power Machinery and Engineering of M.O.E., Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China ... The autoignition of dimethyl ether (DME), an alternative diesel engine fuel, has been studied at elevated pressures. ... In addition to studies aimed at ascertaining the performance of compression–ignition internal combustion engines fuel with DME,(2, 3) there have been a number of studies focused on experimental characterization of fundamental combustion properties for DME. ...

Zhenhua Li; Weijing Wang; Zhen Huang; Matthew A. Oehlschlaeger

2013-04-01T23:59:59.000Z

439

Computer program for Stirling-engine-performance calculations  

SciTech Connect (OSTI)

To support the development of the Stirling engine as a possible alternative to the automobile spark-ignition engine, the thermodynamic characteristics of the Stirling engine were analyzed and modeled on a computer. The computer model is documented. The documentation includes a user's manual, symbols list, a test case, comparison of model predictions with test results, and a description of the analytical equations used in the model.

Tew, R.C. Jr.

1983-01-01T23:59:59.000Z

440

Effect of ignition location on the in-process removal of combustion deposits from the output window of a gas turbine laser ignition system  

Science Journals Connector (OSTI)

The effect of ignition location on the effectiveness of combustion deposit removal from the reverse side of an optical window in a laser ignition system for use in gas turbines is presented. Such deposits consist of carbon and other by-products which accumulate on the walls of the chamber as a result of incomplete combustion. In laser based ignition systems this accumulation of combustion deposits has the potential to reduce the transmissive properties of the output window required for transmission of the laser radiation into the combustion chamber, adversely affecting the likelihood of successful ignition. In this work, a full empirical study into the in-process removal of combustion deposits from the reverse side of the optical window in a laser ignition system using a Q-switched Nd:YAG laser is presented, with an emphasis on the effect of ignition location on the effectiveness of combustion deposit removal. In addition, the mechanism of deposit removal is discussed.

J. Griffiths; J. Lawrence; P. Fitzsimons

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Fast ignition: Dependence of the ignition energy on source and target parameters for particle-in-cell-modelled energy and angular distributions of the fast electrons  

SciTech Connect (OSTI)

The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ?{sup ?2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.

Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2013-05-15T23:59:59.000Z

442

Technologies for Gaseous Fueled Advanced Reciprocating Engine...  

Broader source: Energy.gov (indexed) [DOE]

* A user facility to developtest technologies to improve DE performance. 2 Advanced Laser Ignition System (ALIS): * Laser ignition was shown to extend lean ignitability of...

443

Ignition and Burn in a Small Magnetized Fuel Target  

E-Print Network [OSTI]

LASNEX calculations of a small magnetized target show high gain at a velocity significantly lower than needed for unmagnetized targets. Its cryogenic fuel layer appears to be raised to an equilibrium ignition temperature of about 2 keV by the radiation from the burning magnetized fuel.

Kirkpatrick, Ronald C

2014-01-01T23:59:59.000Z

444

On Operational Power Reactor Regime and Ignited Spherical Tokamaks  

E-Print Network [OSTI]

, 2003 version of the "cold" magnetic "Fusion without ignition" in the next 35 years, the talk.-Pitersburg, St.-Pitersburg, RF % Insutute of Nuclear Fusion, RRC "Kurchatov Ins.", Moscow, RF & Vyoptics, Inc for magnetic fusion, OPRR requires a low recycling and wall-stabilized high- plasma. Because of the small

Zakharov, Leonid E.

445

National Ignition Facility faces an uncertain future David Kramer  

E-Print Network [OSTI]

-member user group, with 22% of its members coming from host Lawrence Livermore National Laboratory (LLNL at the National Ignition Facility to achieve a self-sustaining fusion reaction fell short. Now NIF stands to lose that were specified for NIF when the massive laser facility was ap- proved for construction in 1996

446

Semiconductor bridge: A plasma generator for the ignition of explosives  

SciTech Connect (OSTI)

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics, propellants, and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ..mu..s), low-energy pulse (less than 3.5 mJ), the SCB produces a hot plasma that ignites explosives. The SCB, a heavily n-doped silicon film, typically 100 ..mu..m long by 380 ..mu..m wide by 2 ..mu..m thick, is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one-tenth the input energy of metal bridgewires. In spite of the low energies for ignition, SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process, plasma formation, optical spectra from the discharge, heat transfer mechanisms from the SCB to the explosive powders, and SCB device applications.

Benson, D.A.; Larsen, M.E.; Renlund, A.M.; Trott, W.M.; Bickes R.W. Jr.

1987-09-01T23:59:59.000Z

447

Semiconductor bridge: A plasma generator for the ignition of explosives  

Science Journals Connector (OSTI)

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics propellants and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ?s) low?energy pulse (less than 3.5 mJ) the SCB produces a hot plasma that ignites explosives. The SCB a heavily n?doped silicon film typically 100 ?m long by 380 ?m wide by 2 ?m thick is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one?tenth the input energy of metal bridgewires. In spite of the low energies for ignition SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process plasma formation optical spectra from the discharge heat transfer mechanisms from the SCB to the explosive powders and SCB device applications.

D. A. Benson; M. E. Larsen; A. M. Renlund; W. M. Trott; R. W. Bickes Jr.

1987-01-01T23:59:59.000Z

448

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect (OSTI)

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Li, H.

1990-01-01T23:59:59.000Z

449

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect (OSTI)

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Li, H.

1990-12-31T23:59:59.000Z

450

Ignition of HMX (cyclotetramethylenetetranitramine) using low energy laser diodes  

SciTech Connect (OSTI)

The sensitivity of blends of cyclotetramethylenetetranitramine (HMX) with carbon black and graphite to laser diode ignition was investigated. Using a 100-{mu}m optical fiber, a blend of 15,700 cm{sup 2}/g HMX with 3{percent} carbon black by weight was the most sensitive material tested, with a threshold of 72 mW. Pure, or undoped, HMX could not be ignited using 10 ms laser diode pulses with power levels up to 880 mW. In general, the HMX/carbon black blends were more sensitive than the HMX/graphite blends. HMX specific surface area also had a significant effect on sensitivity. Doubling the spot size increased the ignition threshold by a factor of approximately 2.7. Increasing the pulse width from 10 to 100 ms did not significantly reduce the laser diode power required for ignition. Photoacoustic spectrometer was used to compare the absorption characteristics of the HMX blends. The absorption spectra obtained correlated well with the sensitivity test data. 11 refs., 5 figs., 3 tabs.

Ewick, D.W.; Beckman, T.M.; Holy, J.A.; Thorpe, R.

1990-01-01T23:59:59.000Z

451

Fusion Ignition Research Experiment Princeton Plasma Physics Laboratory  

E-Print Network [OSTI]

Fusion Ignition Research Experiment Dale Meade Princeton Plasma Physics Laboratory Abstract Understanding the properties of high gain (alpha­dominated) fusion plasmas in an advanced toroidal configuration­dominated plasmas in advanced toroidal systems. Technical Challenges for Major Next Steps in Magnetic Fusion Energy

452

Carbon dioxide emission during forest fires ignited by lightning  

E-Print Network [OSTI]

In this paper we developed the model for the carbon dioxide emission from forest fire. The master equation for the spreading of the carbon dioxide to atmosphere is the hyperbolic diffusion equation. In the paper we study forest fire ignited by lightning. In that case the fores fire has the well defined front which propagates with finite velocity.

Magdalena Pelc; Radoslaw Osuch

2009-03-31T23:59:59.000Z

453

Fundamentals of High Pressure Combustion Chapter in High Pressure Processes in Chemical Engineering, Edited by Maximillian Lackner,  

E-Print Network [OSTI]

Fundamentals of High Pressure Combustion Chapter in High Pressure Processes in Chemical Engineering for more than 50 years and are expected to continue to do so [2]. Diesel engines obtain pressures as large as 60atm after ignition [3, 4, 5, 6, 7]. Figure 1 presents a schematic of diesel and gas turbine engine

Miller, Richard S.

454

Ignition characteristics of laser-ablated aluminum at shock pressures up to 2?GPa  

SciTech Connect (OSTI)

The ignition of aluminum particles under high pressure and temperature conditions is considered. The laser ablation method is used to generate oxide-free aluminum particles exposed to pressures ranging between 0.35 and 2.2?GPa. A continuous wave CO{sub 2} laser radiation heats the surface of the aluminum target until ignition is observed. We confirm ignition by a spectroscopic analysis of AlO vibronic band of 484?nm wavelength, and the radiant temperature is measured with respect to various pressures for estimating the heating energy for ignition. The ignition characteristics of the oxide-free aluminum particles exposed to extremely high pressures are reported.

Lee, Kyung-Cheol; Young Lee, Jae; Yoh, Jack J., E-mail: jjyoh@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanakro, Gwanakgu, Seoul 151-742 (Korea, Republic of); Taira, Tsubasa [Division of Applied Physics, Hokkaido University, Sapporo (Japan); Mo Koo, Goon [Department of Aerospace Engineering, University of Maryland, College Park, Maryland 20742 (United States)

2014-01-07T23:59:59.000Z

455

Hydrogen assisted combustion of ethanol in Diesel enginesHydrogen assisted combustion of ethanol in Diesel engines Anil Singh Bika, Luke Franklin, Prof. David B. Kittelson  

E-Print Network [OSTI]

Hydrogen assisted combustion of ethanol in Diesel enginesHydrogen assisted combustion of ethanol a means of using nearly pure ethanol as a diesel engine fuel by using hydrogen rich gases to facilitate of combustion (SOC) · A good diesel fuel has a low ignition delay period and hence a high CN · Ethanol has

Minnesota, University of

456

SPINTHIR: An ignition model for gas turbines  

E-Print Network [OSTI]

MCS 7 Chia Laguna, Cagliari, Sardinia, Italy, September 11-15, 2011 A PRACTICAL MODEL FOR THE HIGH-ALTITUDE RELIGHT OF A GAS TURBINE COMBUSTOR A. Neophytou*,1, E. Mastorakos*, E.S. Richardson**, S. Stow*** and M. Zedda*** em257@eng... :1916-1927, 2010. [7] Naegeli, D. W. and Dodge, L. G. Combust. Sci. Technol., 80:165-184, 1991. [8] Stow, S. and Zedda, M. and Triantaffylidis, A. and Garmory, A. and Mastorakos, E. and Mosbach, T. Conditional Moment Closure LES modelling of an aero-engine...

Neophytou, A; Mastorakos, E

2012-08-28T23:59:59.000Z

457

Simulation of hydrogen and hydrogen-assisted propane ignition in Pt catalyzed microchannel  

SciTech Connect (OSTI)

This paper deals with self-ignition of catalytic microburners from ambient cold-start conditions. First, reaction kinetics for hydrogen combustion is validated with experimental results from the literature, followed by validation of a simplified pseudo-2D microburner model. The model is then used to study the self-ignition behavior of lean hydrogen/air mixtures in a Platinum-catalyzed microburner. Hydrogen combustion on Pt is a very fast reaction. During cold start ignition, hydrogen conversion reaches 100% within the first few seconds and the reactor dynamics are governed by the ''thermal inertia'' of the microburner wall structure. The self-ignition property of hydrogen can be used to provide the energy required for propane ignition. Two different modes of hydrogen-assisted propane ignition are considered: co-feed mode, where the microburner inlet consists of premixed hydrogen/propane/air mixtures; and sequential feed mode, where the inlet feed is switched from hydrogen/air to propane/air mixtures after the microburner reaches propane ignition temperature. We show that hydrogen-assisted ignition is equivalent to selectively preheating the inlet section of the microburner. The time to reach steady state is lower at higher equivalence ratio, lower wall thermal conductivity, and higher inlet velocity for both the ignition modes. The ignition times and propane emissions are compared. Although the sequential feed mode requires slightly higher amount of hydrogen, the propane emissions are at least an order of magnitude lower than the other ignition modes. (author)

Seshadri, Vikram; Kaisare, Niket S. [Department of Chemical Engineering, Indian Institute of Technology - Madras, Chennai 600 036 (India)

2010-11-15T23:59:59.000Z

458

TransForum v9n1 - Omnivorous Engine  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TransForum Vol. 9, No. 1 This Omnivore Likes a Variety of Fuels, Not Foods Omnivorous engine with Thomas Wallner Argonne research engineer Thomas Wallner adjusts the delay on an ion-sensing circuit used to get real-time combustion feedback. When it comes to fuel, Argonne's omnivorous engine doesn't play favorites. It can take down any blend of gasoline, ethanol, butanol and other types of spark-ignited fuel. Though flexible-fuel vehicles have been around since Ford manufactured its Model T to run on both gasoline and ethanol, the omnivorous engine takes the concept to a whole new level. With this project, researchers are working to fashion an engine that allows spark-ignition vehicles to run more efficiently on ethanol and other next-generation alternative fuels.

459

First and second law analysis of a gasoline engine for various compression ratios  

Science Journals Connector (OSTI)

This article presents a comparative energy and exergy analyses of a single cylinder, four-stroke spark-ignition engine for three compression ratios. A Petter engine with variable compression ratio and ignition timing was used to obtain the experimental data at full load conditions for six engine speeds between 1,300 and 2,800 rpm. It was found that the first and the second law efficiencies increased with increasing compression ratio. The maximum extractable power was obtained at the compression ratio 6.2 and observed inversely proportional to the compression ratio.

Adnan Parlak; Yavuz Erbas; Halit Yasar; Hakan Soyhan; Cengiz Deniz

2009-01-01T23:59:59.000Z

460

Electrical, Engineering  

E-Print Network [OSTI]

Sustainable Engineering ­ advance theory and practice of sustainable engineering; provide access to clean Engineering (Ron Askin) Computer Science Computer Systems Engineering Industrial Engineering Informatics and identification Engineering of Matter, Transport, and Energy (Kyle Squires) Aerospace Engineering Chemical

Zhang, Junshan

Note: This page contains sample records for the topic "ignition engines cxs" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Reducing Emissions of a Diesel Engine Using Fumigation Ethanol and a Diesel Oxidation Catalyst  

Science Journals Connector (OSTI)

Reducing Emissions of a Diesel Engine Using Fumigation Ethanol and a Diesel Oxidation Catalyst ... † Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China ... In contrast to the conventional approach of using ethanol in spark-ignition engines, this study demonstrates the potential of ethanol utilization in diesel engines using dual-fuel combustion, where ethanol is injected into the intake manifold and diesel ... ...

K. S. Tsang; Z. H. Zhang; C. S. Cheung; T. L. Chan

2010-10-14T23:59:59.000Z

462

The Department of Mechanical Engineering --Engineering Mechanics  

E-Print Network [OSTI]

such an issue, Argonne has evaluated the use of laser ignition as an alternative to the conventional Capacitance Discharge Ignition (CDI). Initial tests in a static chamber and a rapid compression machine have shown laser worldwide to reduce laser ignition to practice, further improvement in fiber optics' performance and laser

Endres. William J.

463

Novel injector techniques for coal-fueled diesel engines. Final report  

SciTech Connect (OSTI)

This report, entitled ``Novel Injector Techniques for Coal-Fueled Diesel Engines,`` describes the progress and findings of a research program aimed at development of a dry coal powder fuel injector in conjunction with the Thermal Ignition Combustion System (TICS) concept to achieve autoignition of dry powdered coal in a single-cylinder high speed diesel engine. The basic program consisted of concept selection, analysis and design, bench testing and single cylinder engine testing. The coal injector concept which was selected was a one moving part dry-coal-powder injector utilizing air blast injection. Adiabatics has had previous experience running high speed diesel engines on both direct injected directed coal-water-slurry (CWS) fuel and also with dry coal powder aspirated into the intake air. The Thermal Ignition Combustion System successfully ignited these fuels at all speeds and loads without requiring auxiliary ignition energy such as pilot diesel fuel, heated intake air or glow or spark plugs. Based upon this prior experience, it was shown that the highest efficiency and fastest combustion was with the dry coal, but that the use of aspiration of coal resulted in excessive coal migration into the engine lubrication system. Based upon a desire of DOE to utilize a more modern test engine, the previous naturally-aspirated Caterpillar model 1Y73 single cylinder engine was replaced with a turbocharged (by use of shop air compressor and back pressure control valve) single cylinder version of the Cummins model 855 engine.

Badgley, P.R.

1992-09-01T23:59:59.000Z

464

Single rotor turbine engine  

DOE Patents [OSTI]

There has been invented a turbine engine with a single rotor which cools the engine, functions as a radial compressor, pushes air through the engine to the ignition point, and acts as an axial turbine for powering the compressor. The invention engine is designed to use a simple scheme of conventional passage shapes to provide both a radial and axial flow pattern through the single rotor, thereby allowing the radial intake air flow to cool the turbine blades and turbine exhaust gases in an axial flow to be used for energy transfer. In an alternative embodiment, an electric generator is incorporated in the engine to specifically adapt the invention for power generation. Magnets are embedded in the exhaust face of the single rotor proximate to a ring of stationary magnetic cores with windings to provide for the generation of electricity. In this alternative embodiment, the turbine is a radial inflow turbine rather than an axial turbine as used in the first embodiment. Radial inflow passages of conventional design are interleaved with radial compressor passages to allow the intake air to cool the turbine blades.

Platts, David A. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

465

Observation of strong electromagnetic fields around laser-entrance holes of ignition-scale hohlraums in inertial-confinement fusion experiments at the National Ignition Facility  

E-Print Network [OSTI]

Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA 2 Lawrence Livermore National Laboratory, Livermore, CA 94550 USA 3 Los Alamos National Laboratory, Los Alamos, NM) experiments utilizing ignition-scaled hohlraums at the National Ignition Facility (NIF). A striking

466

Optimal conditions for shock ignition of scaled cryogenic deuterium-tritium targets  

SciTech Connect (OSTI)

Within the framework of the shock-ignition (SI) scheme, ignition conditions are reached following the separation of the compression and heating phases. First, the shell is compressed at a sub-ignition implosion velocity; then an intense laser spike is launched at the end of the main drive, leading to the propagation of a strong shock through the precompressed fuel. The minimal laser energy required for ignition of scaled deuterium-tritium (DT) targets is assessed by calculations. A semi-empiric model describing the ignitor shock generation and propagation in the fuel assembly is defined. The minimal power needed in the laser spike pulse to achieve ignition is derived from the hydrodynamic model. Optimal conditions for ignition of scaled targets are explored in terms of laser intensity, shell-implosion velocity, and target scale range for the SI process. Curves of minimal laser requirements for ignition are plotted in the energy-power diagram. The most economic and reliable conditions for ignition of a millimeter DT target are observed in the 240- to 320-km/s implosion velocity range and for the peak laser intensity ranging from {approx}2 Multiplication-Sign 10{sup 15} W/cm{sup 2} up to 5 Multiplication-Sign 10{sup 15} W/cm{sup 2}. These optimal conditions correspond to shock-ignited targets for a laser energy of {approx}250 kJ and a laser power of 100 to 200 TW. Large, self-ignited targets are particularly attractive by offering ignition at a lower implosion velocity and a reduced laser intensity than for conventional ignition. The SI scheme allows for the compression and heating phases of the high power laser energy research facility target to be performed at a peak laser intensity below 10{sup 16} W/cm{sup 2}. A better control of parametric and hydrodynamic instabilities within the SI scheme sets it as an optimal and reliable approach to attain ignition of large targets.

Lafon, M. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France); Ribeyre, X.; Schurtz, G. [University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France)

2013-02-15T23:59:59.000Z

467

Near-frictionless carbon coatings for spark-ignited direct-injected fuel systems. Final report, January 2002.  

SciTech Connect (OSTI)

This report describes an investigation by the Tribology Section of Argonne National Laboratory (ANL) into the use of near-frictionless carbon (NFC) coatings for spark-ignited, direct-injected (SIDI) engine fuel systems. Direct injection is being pursued in order to improve fuel efficiency and enhance control over, and flexibility of, spark-ignited engines. SIDI technology is being investigated by the Partnership for a New Generation of Vehicles (PNGV) as one route towards meeting both efficiency goals and more stringent emissions standards. Friction and wear of fuel injector and pump parts were identified as issues impeding adoption of SIDI by the OTT workshop on ''Research Needs Related to CIDI and SIDI Fuel Systems'' and the resulting report, Research Needs Related to Fuel Injection Systems in CIDI and SIDI Engines. The following conclusions were reached: (1) Argonne's NFC coatings consistently reduced friction and wear in existing and reformulated gasolines. (2) Compared to three commercial DLC coatings, NFC provided the best friction reduction and protection from wear in gasoline and alternative fuels. (3) NFC was successfully deposited on production fuel injectors. (4) Customized wear tests were performed to simulate the operating environment of fuel injectors. (5) Industry standard lubricity test results were consistent with customized wear tests in showing the friction and wear reduction of NFC and the lubricity of fuels. (6) Failure of NFC coatings by tensile crack opening or spallation did not occur, and issues with adhesion to steel substrates were eliminated. (7) This work addressed several of the current research needs of the OAAT SIDI program, as defined by the OTT report Research Needs Related to Fuel Injection Systems in CIDI and SIDI Engines.

Hershberger, J.; Ozturk, O.; Ajayi, O. O.; Woodford, J. B.; Erdemir, A.; Fenske, G. R.

2002-04-05T23:59:59.000Z

468

The National Ignition Facility: enabling fusion ignition for the 21st century  

Science Journals Connector (OSTI)

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, when completed in 2008, will contain a 192-beam, 1.8?MJ, 500?TW, ultraviolet laser system together with a 10?m diameter target chamber and room for 100 diagnostics. NIF is housed in a 26?000?m2 environmentally controlled building and is the world's largest and most energetic laser experimental system. NIF provides a scientific centre for the study of inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures and pressures approaching 108?K and 1011?bar, respectively, conditions that exist naturally only in the interior of stars and planets. NIF is currently configured with four laser beams activated in late 2002. These beams are being regularly used for laser performance and physics experiments, and to date nearly 250 system shots have been conducted. NIF's laser beams have generated 106?kJ in 23?ns pulses of infrared light and over 16?kJ in 3.5?ns pulses at the third harmonic (351?nm). A number of target experimental systems are being commissioned in support of experimental campaigns. This paper provides a detailed look at the NIF laser systems, laser and optical performance, and results from laser commissioning shots. We also discuss NIF's high-energy density and inertial fusion experimental capabilities, the first experiments on NIF, and plans for future capabilities of this unique facility.

George H. Miller; Edward I. Moses; Craig R. Wuest

2004-01-01T23:59:59.000Z

469

Laser design basis for the National Ignition Facility  

SciTech Connect (OSTI)

Controlled nuclear fusion initiated by highly intense laser beams has been the subject of experiment for many years. The National Ignition Facility (NIF) represents the culmination of design efforts to provide a laser facility that will successfully demonstrate fusion ignition in the laboratory. In this so-called inertial confinement approach, energetic driver beams (laser, X-ray, or charged particle) heat the outer surface of a spherical capsule containing deuterium and tritium (DT) fuel. As the capsule surface explosively evaporates, reaction pressure compresses the DT fuel causing the central core of the fuel to reach extreme density and temperature. When the central temperature is high enough, DT fusion reactions occur. The energy released from these reactions further heats the compressed fuel, and fusion burn propagates outward through the colder regions of the capsule much more rapidly than the inertially confined capsule can expand. The resulting fusion reactions yield many times more energy than was absorbed from the driver beams.

Hunt, J.T.; Manes, K.R.; Murray, J.R.; Renard, P.A.; Sawicki, R.; Trenholme, J.B.; Williams, W.

1994-06-01T23:59:59.000Z

470

Hydrodynamic instabilities in beryllium targets for the National Ignition Facility  

SciTech Connect (OSTI)

Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

Yi, S. A., E-mail: austinyi@lanl.gov; Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

2014-09-15T23:59:59.000Z

471

Fast ignition driven by quasi-monoenergetic ions: Optimal ion type and reduction of ignition energies with an ion beam array  

E-Print Network [OSTI]

Fast ignition of inertial fusion targets driven by quasi-monoenergetic ion beams is investigated by means of numerical simulations. Light and intermediate ions such as lithium, carbon, aluminium and vanadium have been considered. Simulations show that the minimum ignition energies of an ideal configuration of compressed Deuterium-Tritium are almost independent on the ion atomic number. However, they are obtained for increasing ion energies, which scale, approximately, as Z^2, where Z is the ion atomic number. Assuming that the ion beam can be focused into 10 {\\mu}m spots, a new irradiation scheme is proposed to reduce the ignition energies. The combination of intermediate Z ions, such as 5.5 GeV vanadium, and the new irradiation scheme allows a reduction of the number of ions required for ignition by, roughly, three orders of magnitude when compared with the standard proton fast ignition scheme.

Honrubia, J J; Hegelich, B M; Murakami, M; Enriquez, C D

2014-01-01T23:59:59.000Z

472

Effect of Gas-to-Liquid Diesel Fuels on Combustion Characteristics, Engine Emissions, and Exhaust Gas Fuel Reforming. Comparative Study  

Science Journals Connector (OSTI)

School of Engineering, Mechanical and Manufacturing Engineering, University of Birmingham, Birmingham B15 2TT, U.K., Shell Global Solutions, Cheshire Innovation Park, Chester CH1 3SH, U.K., Mechanical Engineering, School of Engineering and Design, Brunel University, West London, Uxbridge UB8 3PH, U.K., and Johnson Matthey Technology Centre, Blount's Court, Sonning Common, Reading RG4 9NH, U.K. ... Clearly, the general trend is toward higher efficiency engines and improved fuel economy, something that puts current technology spark ignition (SI) engines in a relatively weak position compared to compression ignition (CI) engines. ... As the diesel engine used in this study was equipped with a pump-line-nozzle-type fuel injection system, all the observed effects may not apply to common rail or unit injection equipped engines. ...

A. Abu-Jrai; A. Tsolakis; K. Theinnoi; R. Cracknell; A. Megaritis; M. L. Wyszynski; S. E. Golunski

2006-10-18T23:59:59.000Z

473

33engineering EnginEEring and  

E-Print Network [OSTI]

33engineering EnginEEring and ThE builT EnvironmEnT www.wits.ac.za/ebe #12;34 guide for applicants 2015 The study of Engineering Career opportunities for engineers are limitless and extend beyond the formal engineering sector. A career in engineering requires special talents ­ engineers need

Wagner, Stephan

474

System safety in Stirling engine development  

SciTech Connect (OSTI)

The Department of Energy has established a number of broad programs aimed at reducing highway fuel consumption. One of the programs addresses the Stirling engine propulsion system as a possible alternative to the conventional spark-ignition engine. The objective of this program is the development, by 1984, of a Stirling engine system having at least 30% improvement in fuel economy (mpg) over production vehicles powered by conventional spark-ignition engines of the same weight and performance, based on equal BTU content of fuel used. The DOE/NASA Stirling Engine Project Office has required that contractors make safety considerations an integral part of all phases of the Stirling engine development program. As an integral part of each engine design subtask, analyses are being evolved to determine possible modes of failure. The accepted system safety analysis techniques (Fault Tree, FMEA, Hazards Analysis, etc.) are being applied in various degrees of extent at the system, subsystem and component levels. The primary objectives are to identify critical failure areas, to enable removal of susceptibility to such failures or their effects from the system and to minimize risk.

Bankaitis, H.

1981-01-01T23:59:59.000Z

475

Exhaust Emissions and Combustion Characteristics of a Direct Injection (DI) Diesel Engine Fueled with Methanol?Diesel Fuel Blends at Different Injection Timings  

Science Journals Connector (OSTI)

Exhaust Emissions and Combustion Characteristics of a Direct Injection (DI) Diesel Engine Fueled with Methanol?Diesel Fuel Blends at Different Injection Timings ... Because of their fuel economy and high reliability, compression-ignition (CI) engines known as diesel engines have been penetrating a number of markets around the world. ...

Mustafa Canakci; Cenk Sayin; Metin Gumus

2008-09-27T23:59:59.000Z

476